Recognition of dichotic digits under pre-cued and post-cued response conditions in young and elderly listeners

A data-driven approach to identify a rapid screener for auditory processing disorder testing referrals in adults

Hearing thresholds form the gold standard assessment in Audiology clinics. However, ~ 10% of adult patients seeking audiological care for self-perceived hearing deficits have thresholds that are normal. Currently, a diagnostic assessment for auditory processing disorder (APD) remains one of the few viable avenues of further care for this patient population, yet there are no standard guidelines for referrals. Here, we identified tests within the APD testing battery that could provide a rapid screener to inform APD referrals in adults. We first analyzed records from the University of Pittsburgh Medical Center (UPMC) Audiology database to identify adult patients with self-perceived hearing difficulties despite normal audiometric thresholds. We then looked at the patients who were referred for APD testing. We examined test performances, correlational relationships, and classification accuracies. Patients experienced most difficulties within the dichotic domain of testing. Additionally, accuracies calculated from sensitivities and specificities revealed the words-in-noise (WIN), the Random Dichotic Digits Task (RDDT) and Quick Speech in Noise (QuickSIN) tests had the highest classification accuracies. The addition of these tests have the greatest promise as a quick screener during routine audiological assessments to help identify adult patients who may be referred for APD assessment and resulting treatment plans.

Effect of a Dichotic Interaural Time Difference Program on Dichotic Listening Deficit of Children with Learning Difficulty

BACKGROUND

 Dichotic listening deficit (DLD) is a common sign in children showing learning problem and is identified during auditory processing assessment. A dichotic listening training program was developed in which the weak ear lags behind the strong ear in time and has certain practices for switching attention between the ears and auditory memory.

PURPOSE

 The aim of the present study was to evaluate the effectiveness of this treatment program on dichotic performance of primary school children showing DLD.

RESEARCH DESIGN

 A pre/post clinical trial without control study.

STUDY SAMPLE

 Twenty-five primary school children, aged 7 to 12 years (mean = 9.3 years), showing DLD.

DATA COLLECTION AND ANALYSIS

 Several primary schools referred the children with learning difficulty to us. We defined learning difficulty as a score of 2 and lower on a five-point scale in at least two primary school courses in the current semester. The children with DLD participated in listening practices three times a week for 10 weeks, each session lasting for 30 minutes. The practices started with one pair of dichotic digits and ended in practice with sentences. The weak ear lag varied from 100 to 1,000 milliseconds. In the last stage of the practices, the precued and postcued directed response aimed at strengthening auditory memory and switching attention between the ears. The results obtained by the tests of dichotic digits, competing words, and competing sentences before and after the intervention were compared using paired t-test. Hedges's g was calculated as the effect size.

RESULTS

 Comparison of the results of pretraining and those of posttraining revealed that the average dominant ear (DE) and nondominant ear (NDE) scores in dichotic listening tests improved significantly with medium-to-large effect sizes. It was also found that the mean change in the NDE score of the children was significantly greater than that of the DE score for all the tests.

CONCLUSIONS

 Dichotic interaural time difference training that employed dichotic lag phenomenon followed by directed response practices significantly improved the DE and the NDE scores of the schoolchildren with DLD.

Suprathreshold Differences in Competing Speech Perception in Older Listeners With Normal and Impaired Hearing

Purpose Age-related declines in auditory temporal processing and cognition make older listeners vulnerable to interference from competing speech. This vulnerability may be increased in older listeners with sensorineural hearing loss due to additional effects of spectral distortion and accelerated cognitive decline. The goal of this study was to uncover differences between older hearing-impaired (OHI) listeners and older normal-hearing (ONH) listeners in the perceptual encoding of competing speech signals. Method Age-matched groups of 10 OHI and 10 ONH listeners performed the coordinate response measure task with a synthetic female target talker and a male competing talker at a target-to-masker ratio of +3 dB. Individualized gain was provided to OHI listeners. Each listener completed 50 baseline and 800 "bubbles" trials in which randomly selected segments of the speech modulation power spectrum (MPS) were retained on each trial while the remainder was filtered out. Average performance was fixed at 50% correct by adapting the number of segments retained. Multinomial regression was used to estimate weights showing the regions of the MPS associated with performance (a "classification image" or CImg). Results The CImg weights were significantly different between the groups in two MPS regions: a region encoding the shared phonetic content of the two talkers and a region encoding the competing (male) talker's voice. The OHI listeners demonstrated poorer encoding of the phonetic content and increased vulnerability to interference from the competing talker. Individual differences in CImg weights explained over 75% of the variance in baseline performance in the OHI listeners, whereas differences in high-frequency pure-tone thresholds explained only 10%. Conclusion Suprathreshold deficits in the encoding of low- to mid-frequency (~5-10 Hz) temporal modulations-which may reflect poorer "dip listening"-and auditory grouping at a perceptual and/or cognitive level are responsible for the relatively poor performance of OHI versus ONH listeners on a different-gender competing speech task. Supplemental Material https://doi.org/10.23641/asha.12568472.

Evaluation of dichotic listening performance in normal-hearing, noise-exposed young females

Recent animal studies have shown that intense noise exposures that produce robust temporary threshold shift (TTS) can inflict irreversible damage to the synaptic connections between the inner hair cells and auditory neurons. It was hypothesized that noise-induced cochlear synaptopathy may cause impaired acoustic encoding in the central auditory nervous system leading to impaired speech perception, particularly in challenging listening situations. The aim of the study was to evaluate the influence of high noise exposure background (NEB) on dichotic listening performance, speech-in-noise performance, and auditory brainstem responses (ABR) measured in young females with normal audiograms. The central hypothesis was that individuals with high NEB would exhibit reduced ABR wave I amplitude and subsequently would exhibit poorer performance on speech-in-noise and dichotic listening. In a sample of 32 females (14 with high NEB and 18 with low NEB) aged 18-35 years, the study compared behavioral hearing thresholds (from 250 to 16000 Hz), distortion-product otoacoustic emissions (DPOAEs, 1000-16000 Hz), click-evoked ABR, QuickSIN signal-to-noise ratio (SNR) loss and dichotic digit test (DDT). The results showed no clear association between NEB, and hearing thresholds, DPOAEs, click-evoked ABR measures, and QuickSIN SNR loss. Individuals with high NEB revealed significantly lower DDT scores and evidence of reduced right ear advantage compared to individuals with low NEB. The poorer performance in DDT and the ear asymmetry in DDT scores with normal ABR findings suggest that high NEB might alter the hemispheric organization of speech-sound processing and cognitive control. The clinical significance of the present findings is discussed.

Spatial attention in bilateral cochlear-implant users

Cochlear-implant (CI) users have difficulty understanding speech in the presence of interfering sounds. This study was designed to determine if binaural unmasking of speech is limited by peripheral or central encoding. Speech was presented to bilateral CI listeners using their clinical processors; unprocessed or vocoded speech was presented to normal-hearing (NH) listeners. Performance was worst for all listener groups in conditions where both the target and interferer were presented monaurally or diotically (i.e., no spatial differences). Listeners demonstrated improved performance compared to the monaural and diotic conditions when the target and interferer were presented to opposite ears. However, only some CI listeners demonstrated improved performance if the target was in one ear and the interferer was presented diotically, and there was no change for the group on average. This is unlike the 12-dB benefit observed in the NH group when presented the CI simulation. The results suggest that CI users can direct attention to a target talker if the target and interferer are presented to opposite ears; however, larger binaural benefits are limited for more realistic listening configurations, likely due to the imprecise peripheral encoding of the two sounds.

A influência dos aspectos cognitivos e dos processos auditivos na aclimatização das próteses auditivas em idosos

OBJETIVO: Verificar os processos de reconhecimento de fala em tarefa monoaural e de escuta dicótica em tarefa de integração binaural, e compará-los com o processamento cognitivo em idosos antes e após o uso de próteses auditivas. MÉTODOS: Participaram 60 idosos, de ambos os gêneros, com faixa etária entre 61 e 85 anos. Os aspectos cognitivos foram avaliados por meio do Mini-Exame do Estado Mental (MEEM) e Escala de Avaliação da Doença de Alzheimer (ADAS-Cog). Para avaliar o reconhecimento de fala em tarefa monoaural e a escuta dicótica em tarefa de integração binaural, foi utilizado o Índice Percentual de Reconhecimento de Fala (IPRF) e o Teste Dicótico de Dígitos (TDD), antes e após o uso da prótese auditiva. Os dados foram apresentados por meio da estatística descritiva e comparados por meio de testes não paramétricos. RESULTADOS: O reconhecimento de fala no IPRF foi baixo (média de 69,6%), e o TDD apresentou melhor reconhecimento de dígitos à orelha direita (média 74,1%) do que à orelha esquerda (média 61,1%). Nos testes de reconhecimento de fala, houve diferença entre as médias da primeira avaliação e da reavaliação após o uso das próteses auditivas. Não houve associação do IPRF com os aspectos cognitivos. Ocorreu associação do TDD com os dois testes cognitivos, especialmente à orelha esquerda. CONCLUSÃO: Todos os indivíduos estavam aclimatizados, pois houve melhora do reconhecimento de fala após o uso das próteses auditivas. Os indivíduos com alteração cognitiva apresentam pior desempenho no processo de reconhecimento da fala em escuta dicótica.

Dichotic word recognition in noise and the right-ear advantage

PURPOSE

This study sought to compare dichotic right-ear advantages (REAs) of young adults to older adult data (C. M. Roup, T. L. Wiley, & R. H. Wilson, 2006) after matching for overall levels of recognition performance. Specifically, speech-spectrum noise was introduced in order to reduce dichotic recognition performance of young adults to a level consistent with that of older adults with hearing loss.

METHOD

Dichotic word-recognition performance was evaluated in the free-recall response paradigm across 2 conditions: (a) quiet and (b) noise (+11 dB signal-to-noise ratio). Participants included a group of right-handed young adults (n = 32) with normal hearing.

RESULTS

The introduction of noise resulted in significantly poorer dichotic word-recognition performance than in the quiet condition for the young adults. REAs, however, did not differ between the 2 conditions. Relative to the Roup et al. (2006) older adult data, performance of the young adults in the noise condition resulted in (a) similar levels of overall recognition performance and (b) significantly smaller REAs.

CONCLUSIONS

Results suggest that the magnitude of the REA is not dependent upon the difficulty of the dichotic task. Rather, the large REAs exhibited by older adults are more likely related to age-related deficits in auditory processing.

Aging effect on dichotic listening of Cantonese

Cantonese dichotic digits recognition was evaluated in free-recall, directed-attention right, and directed-attention left response conditions. All participants were right-handed and included a group of young adults with normal hearing and a group of older adults with minimal sensorineural hearing loss. In all conditions, performance by the young adults was better than performance by the older adults. A right-ear advantage was observed for both groups. Due to a greater deficit in dichotic digits recognition performance in the left ear of older subjects their right-ear advantages were larger than those for the young adults. The results support an age-related disadvantage in recognition performance for dichotic stimuli presented to the left ear of older subjects that is not entirely accounted for by differences in hearing sensitivity between subject groups but may be related to a primary cognitive deficit.

The impact of noise and hearing loss on the processing of simultaneous sentences

OBJECTIVES

To examine the impact of hearing impairment on a listener's ability to process simultaneous spoken messages.

DESIGN

Nine young listeners with bilateral sensorineural hearing loss and nine young listeners with normal hearing participated in this study. Two messages of equal level were presented separately to the two ears. The messages were systematically degraded by adding speech-shaped noise. Listeners performed a single task in which report of one message was required and a dual task in which report of both messages was required.

RESULTS

As the level of the added noise was increased, performance on both single and dual tasks declined. In the dual task, performance on the message reported second was poorer and more sensitive to the noise level than performance on the message reported first. When compared to listeners with normal hearing, listeners with hearing loss showed a larger deficit in recall of the second message than the first. This difference disappeared when performance of the hearing loss group was compared to that of the normal-hearing group at a poorer signal to noise ratio.

CONCLUSIONS

A listener's ability to process a secondary message is more sensitive to noise and hearing impairment than the ability to process a primary message. Tasks involving the processing of simultaneous messages may be useful for assessing hearing handicap and the benefits of rehabilitation in realistic listening scenarios.

Subcortical white matter pathology as a mediating factor for age-related decreased performance in dichotic listening

Cortical 'disconnection', involving disruption of white matter tracts in the brain, has been hypothesized as a mechanism of age-related cognitive decline. Diffuse hyperintensities in the white matter (so called white matter hyperintensities, WMH) on T2-weighted MRI scans are regarded to represent ischemic damage of the subcortical fiber system and are found to be increased with advanced age. In the present study, we examined whether WMH might be a mediating factor for age-effects in dichotic listening. For that purpose, we examined the association between age, deep or subcortical white matter hyperintensities (DWMH), periventricular hyperintensities (PVH) and dichotic listening performance in healthy older adults with ages ranging from 50 to 81 years. We found decreased dichotic listening performance with increasing age, specifically for the left ear (LE) but not the right ear (RE) in a standard unbiased-attention condition, and for the unattended ears but not the attended ears in conditions in which attention was controlled. Interestingly, hierarchical regression analyses revealed that the age-effect is partially mediated by DWMH specifically in the hemisphere contralateral to the attended ear. Moreover, we found indications that RE performance is specifically affected by DWMH in the right and left frontal and temporal areas, and that LE performance is mostly affected by DWMH selectively in the left hemisphere, including the left temporal area. The present study underlines the idea that disconnectivity is involved in age-related cognitive decline.

Failure to control prepotent pathways in early stage dementia of the Alzheimer's type: Evidence from dichotic listening

The authors examined the right ear advantage in a dichotic listening task in healthy aging and very mild and mild stages of Alzheimer's disease. Subjects were simultaneously presented 3 pairs of digits to the left and right ears (e.g., left ear: 4, 3, 1; right ear: 9, 2, 5) for immediate ordered recall. Four lists of triads were presented, varying in presentation rate between digit pairs within a triad (0.5, 1.0, 1.5, 2.0 s). Results indicated that the very mild and mild Alzheimer's groups showed a larger right ear advantage in free recall compared with the healthy controls, indicating a tendency to respond to the prepotent left hemisphere pathway for language processing. Also, the right ear advantage and proportion of switches made during recall were correlated with psychometric measures of frontal lobe function in the mild Alzheimer's group but not in the very mild or healthy control groups.

Effect of order bias on the recognition of dichotic digits in young and elderly listeners

Dichotic listening was evaluated in free-recall and directed-recall (pre-cued, post-cued) response conditions using interleaved one-, two-, and three-pair dichotic digit materials. In the free-recall condition, the subjects recalled in any order the digits presented. In the directed-recall condition, a response task was examined where subjects recalled all digits presented to the cued ear (pre- or post-cued) followed by the digits presented to the opposite (non-cued) ear. Thirty 20- to 29-year-old adults with normal hearing and 30 60- to 79-year-old adults with mild-to-moderate sensorineural hearing loss were evaluated. In all conditions, performance by the younger listeners was better than performance by the elderly listeners. As the difficulty of the dichotic digit task increased, recognition performance decreased. The recognition performance of elderly listeners was more affected by increases in the difficulty of the stimulus materials as compared to the younger listeners. In the free-recall condition, there was a right-ear advantage for both age groups. When instructional bias was imposed, the results favored the ear of instructed bias. The differences in recognition performance between young and elderly listeners likely reflect differences in the difficulty of the dichotic digit test conditions and variations in the demand on auditory memory.