A tonal-language benefit for pitch in normally-hearing and cochlear-implanted children

Factors Associated With Auditory Lifestyle of Adult Cochlear Implant Users

PURPOSE

Auditory lifestyle, which refers to the variety, range, and types of auditory environments individuals encounter in their daily lives, can affect individuals' daily communication functions and moderate the outcomes of hearing interventions. This study aimed to determine the factors associated with adult cochlear implant (CI) users' auditory lifestyle.

METHOD

This observational study included 209 adult CI users. The factors examined included sex, age, social network characteristics, geographical location of residence, cognitive functioning, and speech recognition performance. The Auditory Lifestyle and Demand Questionnaire was used to measure participants' auditory lifestyle. Associations between variables were analyzed using regression models and structural equation modeling.

RESULTS

Regression models indicated that CI users who had larger social networks, were younger or middle aged, and possessed better speech recognition abilities were more likely to experience a diverse and demanding auditory lifestyle. Additionally, sex, age, and cognitive functioning (memory) were associated with the size and diversity of social networks. Finally, structural equation modeling revealed that while age and speech recognition performance were directly related to auditory lifestyle, the impact of age and sex on auditory lifestyle was mediated by the size of social networks.

CONCLUSIONS

Sex, age, size of social networks, and speech recognition ability are associated with CI users' auditory lifestyle. This research highlights the significance of taking into account the demographics and social network characteristics of adult CI users when assessing the auditory environments they experience in their daily lives.

Effects of Masker Intelligibility and Talker Sex on Speech-in-Speech Recognition by Mandarin Speakers Across the Lifespan

OBJECTIVES

Speech perception develops during childhood, matures in early adulthood, and declines in old age. Everyday listening environments often contain competing sounds that may interfere with the perception of the signal of interest. With competing speech, listeners often experience informational masking, where the intelligibility and acoustic characteristics (e.g., talker sex differences) of the maskers interfere with understanding of target speech. Across the lifespan, utilization of segregation cues in competing speech is not well understood. Furthermore, there is a dearth of research regarding speech-in-speech recognition across the lifespan in speakers of tonal languages such as Mandarin Chinese.

DESIGN

Speech recognition thresholds (SRTs) were measured in listeners with age-adjusted normal hearing; the age range of participants was 5 to 74 years old. All participants were native speakers of Mandarin Chinese. SRTs were measured in the presence of two-talker Forward or Reverse speech maskers where the masker sex was the same as or different from the target.

RESULTS

In general, SRTs were highest (poorest) with the Forward same-sex maskers and lowest (best) with the Reverse different-sex maskers. SRT data were analyzed for 5 age groups: child (5 to 9 years), youth (10 to 17 years), adult (18 to 39 years), middle-aged (40 to 59 years), and elderly (60 to 74 years). Overall, SRTs were significantly higher for the child group than for the youth, adult, middle-aged, and elderly groups (p < 0.05), and significantly higher for the elderly than for the adult group (p < 0.05). There was a significant interaction among age group, speech direction, and talker sex cues, where SRTs were significantly higher for Forward than for Reverse speech, and significantly higher for same-sex than for different-sex maskers for all age groups (p < 0.05), except for the child group.

CONCLUSIONS

Consistent with previous studies with non-tonal language speakers, the present SRTs with tonal language speakers were best in the adult group and poorest in the child and elderly groups. The child and youth groups demonstrated greater masking release with Reverse speech than with different-sex maskers, while the elderly group exhibited greater release with the different-sex maskers than with Reverse speech. This pattern of results may reflect developmental effects on utilization of talker sex cues in children; in older adults, enhanced top-down processes may compensate for the age-related declines in processing of temporal envelope and temporal fine structure information.

Audiological performance and subjective satisfaction of the ADHEAR system in experienced pediatric users with unilateral microtia and aural atresia

INTRODUCTION

Despite the reported auditory deficits and developmental challenges in children with unilateral microtia and aural atresia (UMAA), there remains a lack of consensus on early intervention with bone conduction hearing aids (BCHAs) to restore binaural hearing due to the uncertain clinical benefits and intolerability of the conventional devices. Previous studies investigating the auditory benefits under binaural hearing condition were limited and demonstrated controversial opinions in heterogenous patient groups with various devices. Our study aimed to evaluate the audiological performance, including monoaural and binaural hearing, and subjective satisfaction of the ADHEAR system, a novel adhesive BCHA, in experienced pediatric users with UMAA.

METHODS

Twelve children, with a mean age of 9.08 years and previous experience using the ADHEAR system averaging 2.76 years, were included in our final analysis. Auditory performance of monoaural hearing with the affected ears was assessed by sound-field audiometry, speech recognition threshold (SRT), word recognition score (WRS) in quiet and noise. Auditory performance of binaural hearing was assessed by SRT in quiet and noise, along with a virtual sound localization test. Subjective satisfaction was measured with questionnaires.

RESULTS

Monoaural hearing of the affected ears improved in sound-field audiometry (by 18.44 dB HL), SRT (by 17.08 dB HL) and WRS (by 27.00 % in quiet and 30.50 % in noise). Binaural hearing improved in SRT in quiet (by 1.17 dB HL), remained no significant difference in noise and enhanced in sound localization test (reduction of RMS error by 5.96°). The questionnaires indicate satisfying experiences despite skin reactions encountered.

CONCLUSIONS

In children with UMAA under long-term and routine use of the ADHEAR system reveals not only enhancement of audiological performance in the affected ears but also demonstrates potential benefits in speech recognition and sound localization under binaural hearing condition. Users generally expressed satisfaction with the device, while skin reaction is more noticeable in humid subtropical climate.

Pitch perception in school-aged children: Pure tones, resolved and unresolved harmonics

Pitch perception affects children's ability to perceive speech, appreciate music, and learn in noisy environments, such as their classrooms. Here, we investigated pitch perception for pure tones as well as resolved and unresolved complex tones with a fundamental frequency of 400 Hz in 8- to 11-year-old children and adults. Pitch perception in children was better for resolved relative to unresolved complex tones, consistent with adults. The younger 8- to 9-year-old children had elevated thresholds across all conditions, while the 10- to 11-year-old children had comparable thresholds to adults.

Prelingually Deaf Children With Cochlear Implants Show Better Perception of Voice Cues and Speech in Competing Speech Than Postlingually Deaf Adults With Cochlear Implants

OBJECTIVES

Postlingually deaf adults with cochlear implants (CIs) have difficulties with perceiving differences in speakers' voice characteristics and benefit little from voice differences for the perception of speech in competing speech. However, not much is known yet about the perception and use of voice characteristics in prelingually deaf implanted children with CIs. Unlike CI adults, most CI children became deaf during the acquisition of language. Extensive neuroplastic changes during childhood could make CI children better at using the available acoustic cues than CI adults, or the lack of exposure to a normal acoustic speech signal could make it more difficult for them to learn which acoustic cues they should attend to. This study aimed to examine to what degree CI children can perceive voice cues and benefit from voice differences for perceiving speech in competing speech, comparing their abilities to those of normal-hearing (NH) children and CI adults.

DESIGN

CI children's voice cue discrimination (experiment 1), voice gender categorization (experiment 2), and benefit from target-masker voice differences for perceiving speech in competing speech (experiment 3) were examined in three experiments. The main focus was on the perception of mean fundamental frequency (F0) and vocal-tract length (VTL), the primary acoustic cues related to speakers' anatomy and perceived voice characteristics, such as voice gender.

RESULTS

CI children's F0 and VTL discrimination thresholds indicated lower sensitivity to differences compared with their NH-age-equivalent peers, but their mean discrimination thresholds of 5.92 semitones (st) for F0 and 4.10 st for VTL indicated higher sensitivity than postlingually deaf CI adults with mean thresholds of 9.19 st for F0 and 7.19 st for VTL. Furthermore, CI children's perceptual weighting of F0 and VTL cues for voice gender categorization closely resembled that of their NH-age-equivalent peers, in contrast with CI adults. Finally, CI children had more difficulties in perceiving speech in competing speech than their NH-age-equivalent peers, but they performed better than CI adults. Unlike CI adults, CI children showed a benefit from target-masker voice differences in F0 and VTL, similar to NH children.

CONCLUSION

Although CI children's F0 and VTL voice discrimination scores were overall lower than those of NH children, their weighting of F0 and VTL cues for voice gender categorization and their benefit from target-masker differences in F0 and VTL resembled that of NH children. Together, these results suggest that prelingually deaf implanted CI children can effectively utilize spectrotemporally degraded F0 and VTL cues for voice and speech perception, generally outperforming postlingually deaf CI adults in comparable tasks. These findings underscore the presence of F0 and VTL cues in the CI signal to a certain degree and suggest other factors contributing to the perception challenges faced by CI adults.

Tonal language experience facilitates the use of spatial cues for segregating competing speech in bimodal cochlear implant listeners

English-speaking bimodal and bilateral cochlear implant (CI) users can segregate competing speech using talker sex cues but not spatial cues. While tonal language experience allows for greater utilization of talker sex cues for listeners with normal hearing, tonal language benefits remain unclear for CI users. The present study assessed the ability of Mandarin-speaking bilateral and bimodal CI users to recognize target sentences amidst speech maskers that varied in terms of spatial cues and/or talker sex cues, relative to the target. Different from English-speaking CI users, Mandarin-speaking CI users exhibited greater utilization of spatial cues, particularly in bimodal listening.

Predicting emotion perception abilities for cochlear implant users

OBJECTIVE

In daily life, failure to perceive emotional expressions can result in maladjusted behaviour. For cochlear implant users, perceiving emotional cues in sounds remains challenging, and the factors explaining the variability in patients' sensitivity to emotions are currently poorly understood. Understanding how these factors relate to auditory proficiency is a major challenge of cochlear implant research and is critical in addressing patients' limitations.

DESIGN

To fill this gap, we evaluated different auditory perception aspects in implant users (pitch discrimination, music processing and speech intelligibility) and correlated them to their performance in an emotion recognition task.

STUDY SAMPLE

Eighty-four adults (18-76 years old) participated in our investigation; 42 cochlear implant users and 42 controls. Cochlear implant users performed worse than their controls on all tasks, and emotion perception abilities were correlated to their age and their clinical outcome as measured in the speech intelligibility task.

RESULTS

As previously observed, emotion perception abilities declined with age (here by about 2-3% in a decade). Interestingly, even when emotional stimuli were musical, CI users' skills relied more on processes underlying speech intelligibility.

CONCLUSIONS

These results suggest that speech processing remains a clinical priority even when one is interested in affective skills.

Language-to-music transfer effects depend on the tone language: Akan vs. East Asian tone languages

Recent research suggests that speaking a tone language confers benefits in processing pitch in nonlinguistic contexts such as music. This research largely compares speakers of nontone European languages (English, French) with speakers of tone languages in East Asia (Mandarin, Cantonese, Vietnamese, Thai). However, tone languages exist on multiple continents-notably, languages indigenous to Africa and the Americas. With one exception (Bradley, Psychomusicology, 26(4), 337-345, 2016), no research has assessed whether these tone languages also confer pitch processing advantages. Two studies presented a melody change detection task, using quasirandom note sequences drawn from Western major scale tone probabilities. Listeners were speakers of Akan, a tone language of Ghana, plus speakers from previously tested populations (nontone language speakers and East Asian tone language speakers). In both cases, East Asian tone language speakers showed the strongest musical pitch processing, but Akan speakers did not exceed nontone speakers, despite comparable or better instrument change detection. Results suggest more nuanced effects of tone languages on pitch processing. Greater numbers of tones, presence of contour tones in a language's tone inventory, or possibly greater functional load of tone may be more likely to confer pitch processing benefits than mere presence of tone contrasts.

Sustainable Benefits of High Variability Phonetic Training in Mandarin-speaking Kindergarteners With Cochlear Implants: Evidence From Categorical Perception of Lexical Tones

OBJECTIVES

Although pitch reception poses a great challenge for individuals with cochlear implants (CIs), formal auditory training (e.g., high variability phonetic training [HVPT]) has been shown to provide direct benefits in pitch-related perceptual performances such as lexical tone recognition for CI users. As lexical tones in spoken language are expressed with a multitude of distinct spectral, temporal, and intensity cues, it is important to determine the sources of training benefits for CI users. The purpose of the present study was to conduct a rigorous fine-scale evaluation with the categorical perception (CP) paradigm to control the acoustic parameters and test the efficacy and sustainability of HVPT for Mandarin-speaking pediatric CI recipients. The main hypothesis was that HVPT-induced perceptual learning would greatly enhance CI users' ability to extract the primary pitch contours from spoken words for lexical tone identification and discrimination. Furthermore, individual differences in immediate and long-term gains from training would likely be attributable to baseline performance and duration of CI use.

DESIGN

Twenty-eight prelingually deaf Mandarin-speaking kindergarteners with CIs were tested. Half of them received five sessions of HVPT within a period of 3 weeks. The other half served as control who did not receive the formal training. Two classical CP tasks on a tonal continuum from Mandarin tone 1 (high-flat in pitch) to tone 2 (mid-rising in pitch) with fixed acoustic features of duration and intensity were administered before (pretest), immediately after (posttest), and 10 weeks posttraining termination (follow-up test). Participants were instructed to either label a speech stimulus along the continuum (i.e., identification task) or determine whether a pair of stimuli separated by zero or two steps from the continuum was the same or different (i.e., discrimination task). Identification function measures (i.e., boundary position and boundary width) and discrimination function scores (i.e., between-category score, within-category score, and peakedness score) were assessed for each child participant across the three test sessions.

RESULTS

Linear mixed-effects (LME) models showed significant training-induced enhancement in lexical tone categorization with significantly narrower boundary width and better between-category discrimination in the immediate posttest over pretest for the trainees. Furthermore, training-induced gains were reliably retained in the follow-up test 10 weeks after training. By contrast, no significant changes were found in the control group across sessions. Regression analysis confirmed that baseline performance (i.e., boundary width in the pretest session) and duration of CI use were significant predictors for the magnitude of training-induced benefits.

CONCLUSIONS

The stringent CP tests with synthesized stimuli that excluded acoustic cues other than the pitch contour and were never used in training showed strong evidence for the efficacy of HVPT in yielding immediate and sustained improvement in lexical tone categorization for Mandarin-speaking children with CIs. The training results and individual differences have remarkable implications for developing personalized computer-based short-term HVPT protocols that may have sustainable long-term benefits for aural rehabilitation in this clinical population.

Frequency detection, frequency discrimination, and spectro-temporal pattern perception in older and younger typically hearing adults

Elderly adults often experience difficulties in speech understanding, possibly due to age-related deficits in frequency perception. It is unclear whether age-related deficits in frequency perception differ between the apical or basal regions of the cochlea. It is also unclear how aging might differently affect frequency discrimination or detection of a change in frequency within a stimulus. In the present study, pure-tone frequency thresholds were measured in 19 older (61-74 years) and 20 younger (22-28 years) typically hearing adults. Participants were asked to discriminate between reference and probe frequencies or to detect changes in frequency within a probe stimulus. Broadband spectro-temporal pattern perception was also measured using the spectro-temporal modulated ripple test (SMRT). Frequency thresholds were significantly poorer in the basal than in the apical region of the cochlea; the deficit in the basal region was 2 times larger for the older than for the younger group. Frequency thresholds were significantly poorer in the older group, especially in the basal region where frequency detection thresholds were 3.9 times poorer for the older than for the younger group. SMRT thresholds were 1.5 times better for the younger than for the older group. Significant age effects were observed for SMRT thresholds and for frequency thresholds only in the basal region. SMRT thresholds were significantly correlated with frequency thresholds only in the older group. The poorer frequency and spectro-temporal pattern perception may contribute to age-related deficits in speech perception, even when audiometric thresholds are nearly normal.

The effect of lexical tone experience on English intonation perception in Mandarin-speaking cochlear-implanted children

To examine the effect of lexical tone experience on English intonation perception in Mandarin-speaking cochlear-implanted children during second language acquisition in Taiwan. A retrospective cohort study. A tertiary referred center. Fourteen children with cochlear implant (CI) in the experimental group, and 9 normal hearing children in the control group were enrolled in this study. Cochlear implantation and hearing rehabilitation. Two speech recognition accuracies were examined: (1) Lexical tone recognition (4-alternative forced choice, AFC), (2) English Sentence Intonation (2AFC). The overall accuracies for tone perception are 61.13% (standard deviation, SD = 10.84%) for CI group and 93.82% (SD = 1.80%) for normal hearing group. Tone 4 and Tone 1 were more easily to be recognized than tone 2 and tone 3 in the pediatric CI recipients (cCI) group. In English intonation perception, the overall accuracies are 61.82% (SD = 16.85%) for CI group, and 97.59% (SD = 4.73%) for normal hearing group. Significant high correlation (R = .919, P ≦ .000) between lexical tone perception and English intonation perception is noted. There is no significant difference for English intonation perception accuracies between Mandarin-speaking cCI (61.82%) and English-speaking cCI (70.13%, P = .11). Mandarin-speaking cochlear-implanted children showed significant deficits in perception of lexical tone and English intonation relative to normal hearing children. There was no tonal language benefit in Mandarin-speaking cochlear-implanted children's English intonation perception, compared to the English-speaking cochlear-implanted peers. For cochlear-implanted children, better lexical tone perception comes with better English intonation perception. Enhancing Mandarin prosodic perception for cochlear-implanted children may benefit their command of intonation in English.

Voice emotion recognition by Mandarin-speaking pediatric cochlear implant users in Taiwan

OBJECTIVES

To explore the effects of obligatory lexical tone learning on speech emotion recognition and the cross-culture differences between United States and Taiwan for speech emotion understanding in children with cochlear implant.

METHODS

This cohort study enrolled 60 cochlear-implanted (cCI) Mandarin-speaking, school-aged children who underwent cochlear implantation before 5 years of age and 53 normal-hearing children (cNH) in Taiwan. The emotion recognition and the sensitivity of fundamental frequency (F0) changes for those school-aged cNH and cCI (6-17 years old) were examined in a tertiary referred center.

RESULTS

The mean emotion recognition score of the cNH group was significantly better than the cCI. Female speakers' vocal emotions are more easily to be recognized than male speakers' emotion. There was a significant effect of age at test on voice recognition performance. The average score of cCI with full-spectrum speech was close to the average score of cNH with eight-channel narrowband vocoder speech. The average performance of voice emotion recognition across speakers for cCI could be predicted by their sensitivity to changes in F0.

CONCLUSIONS

Better pitch discrimination ability comes with better voice emotion recognition for Mandarin-speaking cCI. Besides the F0 cues, cCI are likely to adapt their voice emotion recognition by relying more on secondary cues such as intensity and duration. Although cross-culture differences exist for the acoustic features of voice emotion, Mandarin-speaking cCI and their English-speaking cCI peer expressed a positive effect for age at test on emotion recognition, suggesting the learning effect and brain plasticity. Therefore, further device/processor development to improve presentation of pitch information and more rehabilitative efforts are needed to improve the transmission and perception of voice emotion in Mandarin.

LEVEL OF EVIDENCE

3.

Reverberation Degrades Pitch Perception but Not Mandarin Tone and Vowel Recognition of Cochlear Implant Users

OBJECTIVES

The primary goal of this study was to investigate the effects of reverberation on Mandarin tone and vowel recognition of cochlear implant (CI) users and normal-hearing (NH) listeners. To understand the performance of Mandarin tone recognition, this study also measured participants' pitch perception and the availability of temporal envelope cues in reverberation.

DESIGN

Fifteen CI users and nine NH listeners, all Mandarin speakers, were asked to recognize Mandarin single-vowels produced in four lexical tones and rank harmonic complex tones in pitch with different reverberation times (RTs) from 0 to 1 second. Virtual acoustic techniques were used to simulate rooms with different degrees of reverberation. Vowel duration and correlation between amplitude envelope and fundamental frequency (F0) contour were analyzed for different tones as a function of the RT.

RESULTS

Vowel durations of different tones significantly increased with longer RTs. Amplitude-F0 correlation remained similar for the falling Tone 4 but greatly decreased for the other tones in reverberation. NH listeners had robust pitch-ranking, tone recognition, and vowel recognition performance as the RT increased. Reverberation significantly degraded CI users' pitch-ranking thresholds but did not significantly affect the overall scores of tone and vowel recognition with CIs. Detailed analyses of tone confusion matrices showed that CI users reduced the flat Tone-1 responses but increased the falling Tone-4 responses in reverberation, possibly due to the falling amplitude envelope of late reflections after the original vowel segment. CI users' tone recognition scores were not correlated with their pitch-ranking thresholds.

CONCLUSIONS

NH listeners can reliably recognize Mandarin tones in reverberation using salient pitch cues from spectral and temporal fine structures. However, CI users have poorer pitch perception using F0-related amplitude modulations that are reduced in reverberation. Reverberation distorts speech amplitude envelopes, which affect the distribution of tone responses but not the accuracy of tone recognition with CIs. Recognition of vowels with stationary formant trajectories is not affected by reverberation for both NH listeners and CI users, regardless of the available spectral resolution. Future studies should test how the relatively stable vowel and tone recognition may contribute to sentence recognition in reverberation of Mandarin-speaking CI users.

Hearing Protection Outcomes of Analog Electrode Arrays Coated with Different Drug-Eluting Polymer Films Implanted into Guinea Pig Cochleae

Objective

To investigate the hearing protection outcomes of different drug-eluting analog electrode arrays implanted into guinea pig cochleae.

Methods

Sixty guinea pigs were randomly divided into a negative control group and five experimental groups implanted separately with blank (drug carrier), dexamethasone (DXM), aracytine (Ara-C), Ara-C+DXM, and nicotinamide adenine dinucleotide (NAD+) eluting analog electrode arrays. Micro CT was used to supervise the surgical procedure. Auditory brainstem response (ABR) thresholds of the guinea pigs were measured and analyzed.

Results and Conclusions

Compared with the negative control, all other groups showed a significant increase in ABR threshold (p<0.001) after surgery. Among them, there was no obvious difference between the blank (0 vs 90 days: 59.70±10.57 vs 64.60±9.47 dB SPL) and the NAD+ group (0 vs 90 days: 59.90±9.87 vs 64.70±8.65 dB SPL). On the other hand, the ABR thresholds in the DXM (0 days: 58.10±10.73 dB SPL; 90 days: 51.70±9.07 dB SPL) and the Ara-C group (0 days: 59.00±10.05 dB SPL; 90 days: 51.60±8.48 dB SPL) decreased significantly compared with the former two groups (p<0.001). However, the Ara-C+DXM group showed no further benefit (p>0.05). In addition, a significantly higher survival rate of spiral ganglion neurons in cochleae was observed in the Ara-C and/or DXM groups.

Improved Auditory Function Caused by Music Versus Foreign Language Training at School Age: Is There a Difference?

In adults, music and speech share many neurocognitive functions, but how do they interact in a developing brain? We compared the effects of music and foreign language training on auditory neurocognition in Chinese children aged 8–11 years. We delivered group-based training programs in music and foreign language using a randomized controlled trial. A passive control group was also included. Before and after these year-long extracurricular programs, auditory event-related potentials were recorded (n = 123 and 85 before and after the program, respectively). Through these recordings, we probed early auditory predictive brain processes.

To our surprise, the language program facilitated the children’s early auditory predictive brain processes significantly more than did the music program. This facilitation was most evident in pitch encoding when the experimental paradigm was musically relevant. When these processes were probed by a paradigm more focused on basic sound features, we found early predictive pitch encoding to be facilitated by music training.

Thus, a foreign language program is able to foster auditory and music neurocognition, at least in tonal language speakers, in a manner comparable to that by a music program. Our results support the tight coupling of musical and linguistic brain functions also in the developing brain.

Three-Dimensional Modeling and Measurement of the Human Cochlear Hook Region: Considerations for Tonotopic Mapping

HYPOTHESIS

Measuring the length of the basilar membrane (BM) in the cochlear hook region will result in improved accuracy of cochlear duct length (CDL) measurements.

BACKGROUND

Cochlear implant pitch mapping is generally performed in a patient independent approach, which has been shown to result in place-pitch mismatches. In order to customize cochlear implant pitch maps, accurate CDL measurements must be obtained. CDL measurements generally begin at the center of the round window (RW) and ignore the basal-most portion of the BM in the hook region. Measuring the size and morphology of the BM in the hook region can improve CDL measurements and our understanding of cochlear tonotopy.

METHODS

Ten cadaveric human cochleae underwent synchrotron radiation phase-contrast imaging. The length of the BM through the hook region and CDL were measured. Two different CDL measurements were obtained for each sample, with starting points at the center of the RW (CDLRW) and the basal-most tip of the BM (CDLHR). Regression analysis was performed to relate CDLRW to CDLHR. A three-dimensional polynomial model was determined to describe the average BM hook region morphology.

RESULTS

The mean CDLRW value was 33.03 ± 1.62 mm, and the mean CDLHR value was 34.68 ± 1.72 mm. The following relationship was determined between CDLRW and CDLHR: CDLHR  = 1.06(CDLRW)-0.26 (R2  = 0.99).

CONCLUSION

The length and morphology of the hook region was determined. Current measurements underestimate CDL in the hook region and can be corrected using the results herein.

Perception of Child-Directed Versus Adult-Directed Emotional Speech in Pediatric Cochlear Implant Users

OBJECTIVES

Cochlear implants (CIs) are remarkable in allowing individuals with severe to profound hearing loss to perceive speech. Despite these gains in speech understanding, however, CI users often struggle to perceive elements such as vocal emotion and prosody, as CIs are unable to transmit the spectro-temporal detail needed to decode affective cues. This issue becomes particularly important for children with CIs, but little is known about their emotional development. In a previous study, pediatric CI users showed deficits in voice emotion recognition with child-directed stimuli featuring exaggerated prosody. However, the large intersubject variability and differential developmental trajectory known in this population incited us to question the extent to which exaggerated prosody would facilitate performance in this task. Thus, the authors revisited the question with both adult-directed and child-directed stimuli.

DESIGN

Vocal emotion recognition was measured using both child-directed (CDS) and adult-directed (ADS) speech conditions. Pediatric CI users, aged 7-19 years old, with no cognitive or visual impairments and who communicated through oral communication with English as the primary language participated in the experiment (n = 27). Stimuli comprised 12 sentences selected from the HINT database. The sentences were spoken by male and female talkers in a CDS or ADS manner, in each of the five target emotions (happy, sad, neutral, scared, and angry). The chosen sentences were semantically emotion-neutral. Percent correct emotion recognition scores were analyzed for each participant in each condition (CDS vs. ADS). Children also completed cognitive tests of nonverbal IQ and receptive vocabulary, while parents completed questionnaires of CI and hearing history. It was predicted that the reduced prosodic variations found in the ADS condition would result in lower vocal emotion recognition scores compared with the CDS condition. Moreover, it was hypothesized that cognitive factors, perceptual sensitivity to complex pitch changes, and elements of each child's hearing history may serve as predictors of performance on vocal emotion recognition.

RESULTS

Consistent with our hypothesis, pediatric CI users scored higher on CDS compared with ADS speech stimuli, suggesting that speaking with an exaggerated prosody-akin to "motherese"-may be a viable way to convey emotional content. Significant talker effects were also observed in that higher scores were found for the female talker for both conditions. Multiple regression analysis showed that nonverbal IQ was a significant predictor of CDS emotion recognition scores while Years using CI was a significant predictor of ADS scores. Confusion matrix analyses revealed a dependence of results on specific emotions; for the CDS condition's female talker, participants had high sensitivity (d' scores) to happy and low sensitivity to the neutral sentences while for the ADS condition, low sensitivity was found for the scared sentences.

CONCLUSIONS

In general, participants had higher vocal emotion recognition to the CDS condition which also had more variability in pitch and intensity and thus more exaggerated prosody, in comparison to the ADS condition. Results suggest that pediatric CI users struggle with vocal emotion perception in general, particularly to adult-directed speech. The authors believe these results have broad implications for understanding how CI users perceive emotions both from an auditory communication standpoint and a socio-developmental perspective.

Speech perception in noise: Masking and unmasking

Speech perception is essential for daily communication. Background noise or concurrent talkers, on the other hand, can make it challenging for listeners to track the target speech (i.e., cocktail party problem). The present study reviews and compares existing findings on speech perception and unmasking in cocktail party listening environments in English and Mandarin Chinese. The review starts with an introduction section followed by related concepts of auditory masking. The next two sections review factors that release speech perception from masking in English and Mandarin Chinese, respectively. The last section presents an overall summary of the findings with comparisons between the two languages. Future research directions with respect to the difference in literature on the reviewed topic between the two languages are also discussed.

Longer Cochlear Implant Experience Leads to Better Production of Mandarin Tones for Early Implanted Children

OBJECTIVES

Children with cochlear implants (CIs) face challenges in acquiring tones, since CIs do not transmit pitch information effectively. It has been suggested that longer CI experience provides additional benefits for children implanted early, enabling them to achieve language abilities similar to that of normal-hearing (NH) children (Colletti 2009). Mandarin is a tonal language with four lexical tones and a neutral tone (T0), characterized by distinct pitch and durational patterns. It has been suggested that early implantation (i.e., before 2 years) greatly benefits the acquisition of Mandarin tones by children with CIs (Tang et al. 2019c). In this study, we extend those findings to investigate the effect of CI experience on the acquisition of Mandarin tones for children implanted early. We asked the extent to which they were able to produce distinct pitch and durational patterns of both lexical tones and T0 as a function of CI experience, and the extent to which their tonal productions were acoustically like that of NH children.

DESIGN

Forty-four NH 3-year olds and 28 children implanted with CIs between 1 and 2 years, aged 3 to 7, were recruited. The children with CIs were grouped according to the length of CI experience: 3 to 6 years, 2 to 3 years, and 1 to 2 years. Lexical tone and T0 productions were elicited using a picture-naming task. Tonal productions from the children with CIs were acoustically analyzed and compared with those from the NH children.

RESULTS

Children with 3 to 6 years of CI experience were able to produce distinct pitch and durational patterns for both lexical tones and T0, with NH-like acoustic realizations. Children with 2 to 3 years of CI experience were also able to produce the expected tonal patterns, although their productions were not yet NH-like. Those with only 1 to 2 years of CI experience, however, were not yet able to produce the distinct acoustic patterns for either lexical tones or T0.

CONCLUSIONS

These results provide acoustic evidence demonstrating that, when Mandarin-speaking children are implanted before the age of 2, only those with 3 to 6 years of experience were able to produce NH-like tones, including both lexical tone and T0. Children with shorter CI experience (less than 3 years) were unable to produce distinct acoustic patterns for the different tones. This suggests that at least 3 years of CI experience is still needed for early implanted children to acquire tonal distinctions similar to those of NH 3-year olds.

Weighting of Prosodic and Lexical-Semantic Cues for Emotion Identification in Spectrally Degraded Speech and With Cochlear Implants

OBJECTIVES

Normally-hearing (NH) listeners rely more on prosodic cues than on lexical-semantic cues for emotion perception in speech. In everyday spoken communication, the ability to decipher conflicting information between prosodic and lexical-semantic cues to emotion can be important: for example, in identifying sarcasm or irony. Speech degradation in cochlear implants (CIs) can be sufficiently overcome to identify lexical-semantic cues, but the distortion of voice pitch cues makes it particularly challenging to hear prosody with CIs. The purpose of this study was to examine changes in relative reliance on prosodic and lexical-semantic cues in NH adults listening to spectrally degraded speech and adult CI users. We hypothesized that, compared with NH counterparts, CI users would show increased reliance on lexical-semantic cues and reduced reliance on prosodic cues for emotion perception. We predicted that NH listeners would show a similar pattern when listening to CI-simulated versions of emotional speech.

DESIGN

Sixteen NH adults and 8 postlingually deafened adult CI users participated in the study. Sentences were created to convey five lexical-semantic emotions (angry, happy, neutral, sad, and scared), with five sentences expressing each category of emotion. Each of these 25 sentences was then recorded with the 5 (angry, happy, neutral, sad, and scared) prosodic emotions by 2 adult female talkers. The resulting stimulus set included 125 recordings (25 Sentences × 5 Prosodic Emotions) per talker, of which 25 were congruent (consistent lexical-semantic and prosodic cues to emotion) and the remaining 100 were incongruent (conflicting lexical-semantic and prosodic cues to emotion). The recordings were processed to have 3 levels of spectral degradation: full-spectrum, CI-simulated (noise-vocoded) to have 8 channels and 16 channels of spectral information, respectively. Twenty-five recordings (one sentence per lexical-semantic emotion recorded in all five prosodies) were used for a practice run in the full-spectrum condition. The remaining 100 recordings were used as test stimuli. For each talker and condition of spectral degradation, listeners indicated the emotion associated with each recording in a single-interval, five-alternative forced-choice task. The responses were scored as proportion correct, where "correct" responses corresponded to the lexical-semantic emotion. CI users heard only the full-spectrum condition.

RESULTS

The results showed a significant interaction between hearing status (NH, CI) and congruency in identifying the lexical-semantic emotion associated with the stimuli. This interaction was as predicted, that is, CI users showed increased reliance on lexical-semantic cues in the incongruent conditions, while NH listeners showed increased reliance on the prosodic cues in the incongruent conditions. As predicted, NH listeners showed increased reliance on lexical-semantic cues to emotion when the stimuli were spectrally degraded.

CONCLUSIONS

The present study confirmed previous findings of prosodic dominance for emotion perception by NH listeners in the full-spectrum condition. Further, novel findings with CI patients and NH listeners in the CI-simulated conditions showed reduced reliance on prosodic cues and increased reliance on lexical-semantic cues to emotion. These results have implications for CI listeners' ability to perceive conflicts between prosodic and lexical-semantic cues, with repercussions for their identification of sarcasm and humor. Understanding instances of sarcasm or humor can impact a person's ability to develop relationships, follow conversation, understand vocal emotion and intended message of a speaker, following jokes, and everyday communication in general.

Effects of language experience on domain-general perceptual strategies

Speech and music are highly redundant communication systems, with multiple acoustic cues signaling the existence of perceptual categories. This redundancy makes these systems robust to the influence of noise, but necessitates the development of perceptual strategies: listeners need to decide how much importance to place on each source of information. Prior empirical work and modeling has suggested that cue weights primarily reflect within-task statistical learning, as listeners assess the reliability with which different acoustic dimensions signal a category and modify their weights accordingly. Here we present evidence that perceptual experience can lead to changes in cue weighting that extend across tasks and across domains, suggesting that perceptual strategies reflect both global biases and local (i.e. task-specific) learning. In two experiments, native speakers of Mandarin (N = 45)-where pitch is a crucial cue to word identity-placed more importance on pitch and less importance on other dimensions compared to native speakers of non-tonal languages English (N = 45) and Spanish (N = 27), during the perception of both English speech and musical beats. In a third experiment, we further show that Mandarin speakers are better able to attend to pitch and ignore irrelevant variation in other dimensions in speech compared to English and Spanish speakers, and even struggle to ignore pitch when asked to attend to other dimensions. Thus, an individual's idiosyncratic auditory perceptual strategy reflects a complex mixture of congenital predispositions, task-specific learning, and biases instilled by extensive experience in making use of important dimensions in their native language.

Adaptation to pitch-altered feedback is independent of one's own voice pitch sensitivity

Monitoring voice pitch is a fine-tuned process in daily conversations as conveying accurately the linguistic and affective cues in a given utterance depends on the precise control of phonation and intonation. This monitoring is thought to depend on whether the error is treated as self-generated or externally-generated, resulting in either a correction or inflation of errors. The present study reports on two separate paradigms of adaptation to altered feedback to explore whether participants could behave in a more cohesive manner once the error is of comparable size perceptually. The vocal behavior of normal-hearing and fluent speakers was recorded in response to a personalized size of pitch shift versus a non-specific size, one semitone. The personalized size of shift was determined based on the just-noticeable difference in fundamental frequency (F0) of each participant’s voice. Here we show that both tasks successfully demonstrated opposing responses to a constant and predictable F0 perturbation (on from the production onset) but these effects barely carried over once the feedback was back to normal, depicting a pattern that bears some resemblance to compensatory responses. Experiencing a F0 shift that is perceived as self-generated (because it was precisely just-noticeable) is not enough to force speakers to behave more consistently and more homogeneously in an opposing manner. On the contrary, our results suggest that the type of the response as well as the magnitude of the response do not depend in any trivial way on the sensitivity of participants to their own voice pitch. Based on this finding, we speculate that error correction could possibly occur even with a bionic ear, typically even when F0 cues are too subtle for cochlear implant users to detect accurately.

Tonal Language Speakers Are Better Able to Segregate Competing Speech According to Talker Sex Differences

Purpose The aim of this study was to compare release from masking (RM) between Mandarin-speaking and English-speaking listeners with normal hearing for competing speech when target-masker sex cues, spatial cues, or both were available. Method Speech recognition thresholds (SRTs) for competing speech were measured in 21 Mandarin-speaking and 15 English-speaking adults with normal hearing using a modified coordinate response measure task. SRTs were measured for target sentences produced by a male talker in the presence of two masker talkers (different male talkers or female talkers). The target sentence was always presented directly in front of the listener, and the maskers were either colocated with the target or were spatially separated from the target (+90°, -90°). Stimuli were presented via headphones and were virtually spatialized using head-related transfer functions. Three masker conditions were used to measure RM relative to the baseline condition: (a) talker sex cues, (b) spatial cues, or (c) combined talker sex and spatial cues. Results The results showed large amounts of RM according to talker sex and/or spatial cues. There was no significant difference in SRTs between Chinese and English listeners for the baseline condition, where no talker sex or spatial cues were available. Furthermore, there was no significant difference in RM between Chinese and English listeners when spatial cues were available. However, RM was significantly larger for Chinese listeners when talker sex cues or combined talker sex and spatial cues were available. Conclusion Listeners who speak a tonal language such as Mandarin Chinese may be able to take greater advantage of talker sex cues than listeners who do not speak a tonal language.

Development of voice perception is dissociated across gender cues in school-age children

Children's ability to distinguish speakers' voices continues to develop throughout childhood, yet it remains unclear how children's sensitivity to voice cues, such as differences in speakers' gender, develops over time. This so-called voice gender is primarily characterized by speakers' mean fundamental frequency (F0), related to glottal pulse rate, and vocal-tract length (VTL), related to speakers' size. Here we show that children's acquisition of adult-like performance for discrimination, a lower-order perceptual task, and categorization, a higher-order cognitive task, differs across voice gender cues. Children's discrimination was adult-like around the age of 8 for VTL but still differed from adults at the age of 12 for F0. Children's perceptual weight attributed to F0 for gender categorization was adult-like around the age of 6 but around the age of 10 for VTL. Children's discrimination and weighting of F0 and VTL were only correlated for 4- to 6-year-olds. Hence, children's development of discrimination and weighting of voice gender cues are dissociated, i.e., adult-like performance for F0 and VTL is acquired at different rates and does not seem to be closely related. The different developmental patterns for auditory discrimination and categorization highlight the complexity of the relationship between perceptual and cognitive mechanisms of voice perception.

Neurophysiological Differences in Emotional Processing by Cochlear Implant Users, Extending Beyond the Realm of Speech

OBJECTIVE

Cochlear implants (CIs) restore a sense of hearing in deaf individuals. However, they do not transmit the acoustic signal with sufficient fidelity, leading to difficulties in recognizing emotions in voice and in music. The study aimed to explore the neurophysiological bases of these limitations.

DESIGN

Twenty-two adults (18 to 70 years old) with CIs and 22 age-matched controls with normal hearing participated. Event-related potentials (ERPs) were recorded in response to emotional bursts (happy, sad, or neutral) produced in each modality (voice or music) that were for the most part correctly identified behaviorally.

RESULTS

Compared to controls, the N1 and P2 components were attenuated and prolonged in CI users. To a smaller degree, N1 and P2 were also attenuated and prolonged in music compared to voice, in both populations. The N1-P2 complex was emotion-dependent (e.g., reduced and prolonged response to sadness), but this was also true in both populations. In contrast, the later portion of the response, between 600 and 850 ms, differentiated happy and sad from neutral stimuli in normal hearing but not in CI listeners.

CONCLUSIONS

The early portion of the ERP waveform reflected primarily the general reduction in sensory encoding by CI users (largely due to CI processing itself), whereas altered emotional processing (by CI users) could be found in the later portion of the ERP and extended beyond the realm of speech.

Characterization of the human helicotrema: implications for cochlear duct length and frequency mapping

Background

Despite significant anatomical variation amongst patients, cochlear implant frequency-mapping has traditionally followed a patient-independent approach. Basilar membrane (BM) length is required for patient-specific frequency-mapping, however cochlear duct length (CDL) measurements generally extend to the apical tip of the entire cochlea or have no clearly defined end-point. By characterizing the length between the end of the BM and the apical tip of the entire cochlea (helicotrema length), current CDL models can be corrected to obtain the appropriate BM length. Synchrotron radiation phase-contrast imaging has made this analysis possible due to the soft-tissue contrast through the entire cochlear apex.

Methods

Helicotrema linear length and helicotrema angular length measurements were performed on synchrotron radiation phase-contrast imaging data of 14 cadaveric human cochleae. On a sub-set of six samples, the CDL to the apical tip of the entire cochlea (CDL_TIP) and the BM length (CDL_BM) were determined. Regression analysis was performed to assess the relationship between CDL_TIP and CDL_BM.

Results

The mean helicotrema linear length and helicotrema angular length values were 1.6 ± 0.9 mm and 67.8 ± 37.9 degrees, respectively. Regression analysis revealed the following relationship between CDL_TIP and CDL_BM: CDL_BM = 0.88(CDL_TIP) + 3.71 (R² = 0.995).

Conclusion

This is the first known study to characterize the length of the helicotrema in the context of CDL measurements. It was determined that the distance between the end of the BM and the tip of the entire cochlea is clinically consequential. A relationship was determined that can predict the BM length of an individual patient based on their respective CDL measured to the apical tip of the cochlea.

Voice fundamental frequency differences and speech recognition with noise and speech maskers in cochlear implant recipients

Cochlear implant (CI) recipients are limited in their perception of voice cues, such as the fundamental frequency (F0). This has important consequences for speech recognition when several talkers speak simultaneously. This examination considered the comparison of clear speech and noise-vocoded sentences as maskers. For the speech maskers it could be shown that good CI performers are able to benefit from F0 differences between target and masker. This was due to the fact that a F0 difference of 80 Hz significantly reduced target-masker confusions, an effect that was slightly more pronounced in bimodal than in bilateral users.

Processing of Acoustic Information in Lexical Tone Production and Perception by Pediatric Cochlear Implant Recipients

Purpose: This study examined the utilization of multiple types of acoustic information in lexical tone production and perception by pediatric cochlear implant (CI) recipients who are native speakers of Mandarin Chinese. Methods: Lexical tones were recorded from CI recipients and their peers with normal hearing (NH). Each participant was asked to produce a disyllabic word, yan jing, with which the first syllable was pronounced as Tone 3 (a low dipping tone) while the second syllable was pronounced as Tone 1 (a high level tone, meaning "eyes") or as Tone 4 (a high falling tone, meaning "eyeglasses"). In addition, a parametric manipulation in fundamental frequency (F0) and duration of Tones 1 and 4 used in a lexical tone recognition task in Peng et al. (2017) was adopted to evaluate the perceptual reliance on each dimension. Results: Mixed-effect analyses of duration, intensity, and F0 cues revealed that NH children focused exclusively on marking distinct F0 contours, while CI participants shortened Tone 4 or prolonged Tone 1 to enhance their contrast. In line with these production strategies, NH children relied primarily on F0 cues to identify the two tones, whereas CI children showed greater reliance on duration cues. Moreover, CI participants who placed greater perceptual weight on duration cues also tended to exhibit smaller changes in their F0 production. Conclusion: Pediatric CI recipients appear to contrast the secondary acoustic dimension (duration) in addition to F0 contours for both lexical tone production and perception. These findings suggest that perception and production strategies of lexical tones are well coupled in this pediatric CI population.