[Test-retest reliability of the Freiburg monosyllabic speech test]

Investigation of Maximum Monosyllabic Word Recognition as a Predictor of Speech Understanding with Cochlear Implant

Background: The cochlear implant (CI) is an established treatment option for patients with inadequate speech understanding and insufficient aided scores. Nevertheless, reliable predictive models and specific therapy goals regarding achievable speech understanding are still lacking. Method: In this retrospective study, 601 cases of CI fittings between 2005 and 2021 at the University Medical Center Freiburg were analyzed. We investigated the preoperative unaided maximum word recognition score (mWRS) as a minimum predictor for post-interventional scores at 65 dB SPL, WRS65(CI). The WRS65(CI) was compared with the preoperative-aided WRS, and a previously published prediction model for the WRS65(CI) was reviewed. Furthermore, the effect of duration of hearing loss, duration of HA fitting, and etiology on WRS65(CI) were investigated. Results: In 95.5% of the cases, a significant improvement in word recognition was observed after CI. WRS65(CI) achieved or exceeded mWRS in 97% of cases. Etiology had a significant impact on WRS65(CI). The predicted score was missed by more than 20 percentage points in 12.8% of cases. Discussion: Our results confirmed the minimum prediction via mWRS. A more precise prediction of the expected WRS65(CI) is possible. The etiology of hearing loss should be considered in the indication and postoperative care to achieve optimal results.

Prediction of postoperative speech comprehension with the transcutaneous partially implantable bone conduction hearing system Osia®

BACKGROUND

The active transcutaneous, partially implantable osseointegrated bone conduction system Cochlear™ Osia® (Cochlear, Sydney, Australia) has been approved for use in German-speaking countries since April 2021. The Osia is indicated for patients either having conductive (CHL) or mixed hearing loss (MHL) with an average bone conduction (BC) hearing loss of 55 dB HL or less, or having single-sided deafness (SSD).

OBJECTIVES

The aim of this retrospective study was to investigate the prediction of postoperative speech recognition with Osia® and to evaluate the speech recognition of patients with MHL and in particular an aided dynamic range of less than 30 dB with Osia®.

MATERIALS AND METHODS

Between 2017 and 2022, 29 adult patients were fitted with the Osia®, 10 patients (11 ears) with CHL and 19 patients (25 ears) with MHL. MHL was subdivided into two groups: MHL‑I with four-frequency pure-tone average in BC (BC-4PTA) ≥ 20 dB HL and < 40 dB HL (n = 15 patients; 20 ears) vs. MHL-II with BC-4PTA ≥ 40 dB HL (n = 4 patients; 5 ears). All patients tested a bone conduction hearing device on a softband preoperatively. Speech intelligibility in quiet was assessed preoperatively using the Freiburg monosyllabic test in unaided condition, with the trial BCHD preoperatively and with Osia® postoperatively with Osia®. The maximum word recognition score (mWRS) unaided and the word recognition score (WRS) with the test system at 65 dB SPL were correlated with the postoperative WRS with Osia® at 65 dB SPL.

RESULTS

Preoperative prediction of postoperative outcome with Osia® was better using the mWRS than by the WRS at 65 dB SPL with the test device on the softband. Postoperative WRS was most predictive for patients with CHL and less predictable for patients with mixed hearing loss with BC-4PTA ≥ 40 dB HL. For the test device on a softband, the achievable outcome tended to a minimum, with the mWRS tending to predict the realistically achievable outcome.

CONCLUSION

Osia® can be used for the treatment of CHL and MHL within the indication limits. The average preoperative bone conduction hearing threshold also provides an approximate estimate of the postoperative WRS with Osia®, for which the most accurate prediction is obtained using the preoperative mWRS. Prediction accuracy decreases from a BC-4PTA of ≥ 40 dB HL.

Word Recognition with a Cochlear Implant in Relation to Prediction and Electrode Position

BACKGROUND

the word recognition score (WRS) achieved with cochlear implants (CIs) varies widely. To account for this, a predictive model was developed based on patients' age and their pre-operative WRS. This retrospective study aimed to find out whether the insertion depth of the nucleus lateral-wall electrode arrays contributes to the deviation of the CI-achieved WRS from the predicted WRS.

MATERIALS AND METHODS

patients with a pre-operative maximum WRS > 0 or a pure-tone audiogram ≥80 dB were included. The insertion depth was determined via digital volume tomography.

RESULTS

fifty-three patients met the inclusion criteria. The median WRS achieved with the CI was 70%. The comparison of pre- and post-operative scores achieved with a hearing aid and a CI respectively in the aided condition showed a median improvement of 65 percentage points (pp). A total of 90% of the patients improved by at least 20 pp. The majority of patients reached or exceeded the prediction, with a median absolute error of 11 pp. No significant correlation was found between the deviation from the predicted WRS and the insertion depth.

CONCLUSIONS

our data support a previously published model for the prediction of the WRS after cochlear implantation. For the lateral-wall electrode arrays evaluated, the insertion depth did not influence the WRS with a CI.

Evolving a Model for Cochlear Implant Outcome

BACKGROUND

Cochlear implantation is an efficient treatment for postlingually deafened adults who do not benefit sufficiently from acoustic amplification. Implantation is indicated when it can be foreseen that speech recognition with a cochlear implant (CI) is superior to that with a hearing aid. Especially for subjects with residual speech recognition, it is desirable to predict CI outcome on the basis of preoperative audiological tests.

PURPOSE

The purpose of the study was to extend and refine a previously developed model for CI outcome prediction for subjects with preoperative word recognition to include subjects with no residual hearing by incorporating additional results of routine examinations.

RESULTS

By introducing the duration of unaided hearing loss (DuHL), the median absolute error (MAE) of the prediction was reduced. While for subjects with preoperative speech recognition, the model modification did not change the MAE, for subjects with no residual speech recognition before surgery, the MAE decreased from 23.7% with the previous model to 17.2% with the extended model.

CONCLUSIONS

Prediction of word recognition with CI is possible within clinically relevant limits. Outcome prediction is particularly important for preoperative counseling and in CI aftercare to support systematic monitoring of CI fitting.

[Prediction of speech understanding with the transcutaneous partially implantable bone conduction hearing system Osia®. German Version]

BACKGROUND

The active transcutaneous, partially implantable osseointegrated bone conduction system Cochlear™ Osia® (Cochlear, Sydney, Australia) has been approved for use in German-speaking countries since April 2021. The Osia is indicated for patients with conductive (CHL) or mixed hearing loss (MHL) with an average bone conduction (BC) hearing loss of 55 dB or less, or with single-sided deafness (SSD).

OBJECTIVES

The aim of this retrospective study was to investigate the prediction of postoperative speech recognition with Osia and to evaluate the speech recognition of patients with MHL and an aided dynamic range of less than 30 dB with Osia.

MATERIALS AND METHODS

Between 2017 and 2022, 29 adult patients were fitted with the Osia, 10 patients (11 ears) with CHL and 19 patients (21 ears) with MHL. MHL was subdivided into two groups: MHL‑I with four-frequency pure-tone average in BC (BC-4PTA) ≥ 20 dB HL and < 40 dB HL (n = 15 patients; 20 ears) vs. MHL-II with BC-4PTA ≥ 40 dB HL (n = 4 patients; 5 ears). All patients tested a bone conduction hearing device on a softband preoperatively. Speech intelligibility in quiet was assessed preoperatively using the Freiburg monosyllabic test unaided and with the test system and postoperatively with Osia. The maximum monosyllabic score (mEV) unaided and the monosyllabic score with the test system at 65 dB SPL were correlated with the postoperative monosyllabic score with Osia at 65 dB SPL.

RESULTS

Preoperative prediction of postoperative outcome with Osia was better using the mEV than the EV at 65 dB SPL with the test device on the softband. Postoperative EV was most predictive for patients with CHL and least predictive for patients with mixed hearing loss with 4PTA BC ≥ 40 dB HL. For the test device at softband, results tended to show the minimum achievable outcome and the mEV tended to predict the realistically achievable outcome.

CONCLUSION

Osia can be used for the treatment of CHL and MHL within the indication limits. The average preoperative bone conduction hearing threshold also provides an approximate estimate of the postoperative EV with Osia, for which the most accurate prediction is obtained using the preoperative mEV. Prediction accuracy decreases from a BC-4PTA of ≥ 40 dB.

Validation of a predictive model for speech discrimination after cochlear impIant provision

BACKGROUND

If sufficient speech discrimination is no longer achieved with conventional hearing systems, an audiological indication for a cochlear implant (CI) is given. However, there are no established target criteria for CI aftercare with regard to the level of speech comprehension to be achieved. The aim of this study is to validate an existing predictive model for speech comprehension after CI provision. This is applied to different patient groups.

MATERIALS AND METHODS

The prospective study included 124 postlingually deaf adults. The model is based on preoperative maximum monosyllabic recognition score, aided monosyllabic recognition score at 65 dBSPL, and age the time of implantation. The model was investigated with regard to prediction accuracy for monosyllabic recognition with CI after 6 months.

RESULTS

Mean speech discrimination improved from 10% with hearing aid to 65% with CI after 6 months, with a statistically significant improvement in 93% of cases. Deterioration of aided unilateral speech discrimination was not observed. The mean prediction error was 11.5 percentage points in the cases with preoperative scores better than zero and 23.2 percentage points in all other cases.

CONCLUSION

Cochlear implantation should also be considered in patients with moderately severe to severe hearing loss and insufficient speech discrimination with hearing aids. The model based on preoperatively measured data for predicting speech discrimination with CI can be used in preoperative consultation and in the context of postoperative quality assurance.

Extended Preoperative Audiometry for Outcome Prediction and Risk Analysis in Patients Receiving Cochlear Implants

BACKGROUND

The outcome of cochlear implantation has improved over the last decades, but there are still patients with less benefit. Despite numerous studies examining the cochlear implant (CI) outcome, variations in speech comprehension with CI remains incompletely explained. The aim of this study was therefore to examine preoperative pure-tone audiogram and speech comprehension as well as aetiology, to investigate their relationship with postoperative speech comprehension in CI recipients.

METHODS

A retrospective study with 664 ears of 530 adult patients was conducted. Correlations between the target variable postoperative word comprehension with the preoperative speech and sound comprehension as well as aetiology were investigated. Significant correlations were inserted into multivariate models. Speech comprehension measured as word recognition score at 70 dB with CI was analyzed as (i) a continuous and (ii) a dichotomous variable.

RESULTS

All variables that tested preoperative hearing were significantly correlated with the dichotomous target; with the continuous target, all except word comprehension at 65 dB with hearing aid. The strongest correlation with postoperative speech comprehension was seen for monosyllabic words with hearing aid at 80 dB. The preoperative maximum word comprehension was reached or surpassed by 97.3% of CI patients. Meningitis and congenital diseases were strongly negatively associated with postoperative word comprehension. The multivariate model was able to explain 40% of postoperative variability.

CONCLUSION

Speech comprehension with hearing aid at 80 dB can be used as a supplementary preoperative indicator of CI-aided speech comprehension and should be measured regularly in the clinical routine. Combining audiological and aetiological variables provides more insights into the variability of the CI outcome, allowing for better patient counselling.

[Validation of a predictive model for speech discrimination after cochlear implant provision]

BACKGROUND

If sufficient speech discrimination is no longer achieved with conventional hearing systems, an audiological indication for a cochlear implant (CI) is given. However, there are no established target criteria for CI aftercare with regard to the level of speech comprehension to be achieved. The aim of this study is to validate an existing predictive model for speech comprehension after CI provision. This is applied to different patient groups.

MATERIALS AND METHODS

The prospective study included 124 postlingually deaf adults. The model is based on preoperative maximum monosyllabic recognition score, aided monosyllabic recognition score at 65 dB_SPL, and age the time of implantation. The model was investigated with regard to prediction accuracy for monosyllabic recognition with CI after 6 months.

RESULTS

Mean speech discrimination improved from 10% with hearing aid to 65% with CI after 6 months, with a statistically significant improvement in 93% of cases. Deterioration of aided unilateral speech discrimination was not observed. The mean prediction error was 11.5 percentage points in the cases with preoperative scores better than zero and 23.2 percentage points in all other cases.

CONCLUSION

Cochlear implantation should also be considered in patients with moderately severe to severe hearing loss and insufficient speech discrimination with hearing aids. The model based on preoperatively measured data for predicting speech discrimination with CI can be used in preoperative consultation and in the context of postoperative quality assurance.

[Correlation between the APHAB questionnaire and the Freiburg monosyllabic test without + with noise]

BACKGROUND

Questionnaires, e. g. the APHAB, and speech-audiometry are the most used elements in measuring the success of hearing aid fitting (HAF). This study investigates the correlations between the results of the Freiburg monosyllabic word test without and with noise (FBE, FBE-S) and the results of the APHAB before and after HAF.

METHODS

Data of the FBE, the FBE-S, and the APHAB, generated within HAF of 156 subjects were analyzed. After exclusion of a normal distribution of the data, Spearman's correlation and Cohen's effect size were determined.

RESULTS

73 (46.8 %) of the 156 subjects were females, and 83 (53.2 %) males. No significant correlation could be found between the EC-, the RV-, and the cumulative ECBNRV-subscale and the benefit of HAF in the FBE and FBE-S (EC: ease of communication, BN: background noise, RV: reverberation). Most of the remaining coefficients of correlation had a weak positive effect size. A middle positive effect size could only be demonstrated for 6 combinations, for the EC-subscale mostly.

CONCLUSION

The not strong effect sizes could assume that the results in speech-audiometry and the APHAB are not independent and complementing each other as parameters of hearing loss and benefit in HAF. The effect size could be explained by individually different possibilities for the compensation of hearing loss.

Scalar position, dislocation analysis and outcome in CI reimplantation due to device failure

Objective

Due to increasing indication for cochlear implantation (CI), reimplantation and technical upgrades their consequences are a special focus in CI surgery research. The aim of this study is to examine the indication and influences on both morphological position of the electrode array and audiological outcome following reimplantation.

Design

This is a retrospective analysis of adult CI patients reimplanted between 2004 and 2019. We evaluated the scalar position in pre- and postoperative cone beam computed tomography (CBCT) after CI and reimplantation and examined the indication for and the audiological outcome following reimplantation.

Results

The reimplanted patients showed stable and comparable audiological results for monosyllables and numbers for best fitted situation before and following reimplantation. Technical upgrades did not result in a significant improvement of speech perception. CBCT scans of reimplanted ears did not show significant increased rates of scalar dislocation or partial insertion.

Conclusion

Even with a technical upgrade, reimplantation does not improve speech perception outcome in CI patients. Therefore, the indication to reimplant should be approved critically. Reimplantation does not lead to a significantly increased risk for partial insertion, scalar dislocation or diminished electrode array insertion angle.

Wirksamkeit der Hörgeräteversorgung bei hochgradigem Hörverlust

Hintergrund

In der Praxis liegt das unilaterale Einsilberverstehen mit Hörgerät bei 65 dB SPL (EV₆₅(HG)) häufig unter dem maximalen Einsilberverstehen aus dem Sprachaudiogramm (mEV), insbesondere bei Hörgeräteträgern mit hochgradigem Hörverlust. Diese Arbeit zielte darauf ab, den Wirkungsgrad Q der Hörgeräteversorgung, den Quotienten aus EV₆₅(HG) und mEV, bei Hörgeräteträgern mit hochgradigem bis an Taubheit grenzendem Hörverlust zu untersuchen.

Material und Methoden

Es wurden Daten aus In-situ-Messungen, dem Reinton- und Sprachaudiogramm und dem Sprachverstehen mit und ohne Hörgerät von 93 Ohren von 64 Patienten ausgewertet. Die Patienten stellten sich im Jahr 2019 für eine Hörgerätekontrolle in unserem Hörzentrum vor. Es wurden die Abweichung der in-situ gemessenen frequenzabhängigen Ausgangspegelwerte von den Zielvorgaben der präskriptiven Anpassformeln NAL-NL2 und DSL v5.0 analysiert. Für die Parameter EV₆₅(HG) und Q wurden jeweils die Spearman-Korrelationskoeffizienten für den Sprachverständlichkeitsindex (SII) berechnet.

Ergebnisse

Bei mehr als 67 % der Hörgeräteeinstellungen stimmten die Ausgangspegelwerte mit den Zielkurven für NAL-NL2 oder DSL v5.0 im Bereich von ±5 dB für Frequenzen von 0,5 bis 4 kHz für 65 dB SPL überein. Trotzdem wurde das mEV mit Hörgerät bei 65 dB SPL nicht erreicht (mittlere Abweichungen: 34,4 %). EV₆₅(HG) und Q waren jedoch am besten, wenn Zielwerte für DSL v5.0 bei 65 dB SPL erreicht wurden, was mit einem höheren SII einhergeht.

Schlussfolgerung

Für Hörgeräteträger mit hochgradigem bis an Taubheit grenzendem Hörverlust führen die Anpassformeln NAL-NL2 und DSL v5.0 nicht zu einer solchen Verstärkung, dass bei Alltagssprache von 65 dB SPL das mEV erreicht wird. Es bleibt zu untersuchen, ob alternative Präskriptionen mit besserer Hörbarkeit für Eingangspegel von 50 und 65 dB SPL den Wirkungsgrad der Hörgeräteversorgung verbessern könnten.

A Comparative Study of a Novel Adhesive Bone Conduction Device and Conventional Treatment Options for Conductive Hearing Loss

Objective:

To compare the audiological performance with the novel adhesive bone conduction hearing device (ADHEAR) to that with a passive bone conduction (BC) implant and to that with a bone conduction device (BCD) on a softband.

Study Design:

Prospective study in an acute setting, single-subject repeated measure in three situations: unaided, with conventional BCDs (passive implant or on softband), and with the ADHEAR.

Setting:

Tertiary referral center.

Patients:

Ten subjects with conductive hearing loss were evaluated with the ADHEAR. Five of these were users of a passive BC implant (Baha Attract with Baha4); five received a BCD (Baha4) on a softband for test purposes.

Intervention:

Use of non-invasive adhesive bone conduction system for the treatment of conductive hearing loss.

Main Outcome Measures:

Air and bone conduction thresholds, sound field thresholds, word recognition scores in quiet, and speech recognition thresholds in quiet and noise were assessed.

Results:

Users of the passive BC implant received comparable hearing benefit with the ADHEAR. The mean aided thresholds in sound field measurements and speech understanding in quiet and noise were similar, when subjects were evaluated either with the ADHEAR or the passive BC implant. The audiological outcomes for the non-implanted group were also comparable between the ADHEAR and the BCD on softband.

Conclusions:

Based on our initial data, the ADHEAR seems to be a suitable alternative for patients who need a hearing solution for conductive hearing loss but for medical reasons cannot or do not want to undergo surgery for a passive BC implant.

Die Verständlichkeitskurve für den Freiburger Einsilbertest im Störschall mit einem Signal-Rausch-Abstand (SNR) von 5 dB

Hintergrund

Der Freiburger Einsilbertest (FBE) ist seit Langem einer der wesentlichen deutschen Sprachhörtests. Seit einiger Zeit wird er auch zur Messung der Hörverbesserung im Rahmen einer Hörgeräteversorgung im Störschall verwendet (FBE-S). Mit dieser Studie soll eine Verständlichkeitskurve für den Freiburger Einsilbertest im Störschall mit fixem Signal-Störschall-Verhältnis von 5 dB bei verschiedenen Schalldruckpegeln bestimmt werden.

Methode

Im Herbst 2018 wurden 60 normalhörende, muttersprachlich Deutsch sprechende Probanden im Alter zwischen 18 und 31 Jahren in der Klinik für HNO-Heilkunde des Bundeswehrkrankenhauses in Hamburg untersucht. Das Sprachverstehen wurde mit einer Testliste des FBE mit einem Schalldruckpegel von 15 bis 90 dB und einem 5 dB niedrigeren Störschall in 5‑dB-Schritten gemessen. Anschließend wurden von den Verständlichkeitsquoten die Mittelwerte gebildet und die 95%-Konfidenzintervalle (95%-KI) bestimmt.

Ergebnisse

Es nahmen 29 weibliche und 31 männliche Probanden an der Untersuchung teil. Das mittlere Alter aller Probanden betrug 24,32 Jahre (±3,39 Jahre). In der Varianzanalyse für fixe Effekte mit der Verständlichkeit als abhängiger Variablen zeigte sich ein hochsignifikanter Zusammenhang zwischen den Schalldruckpegeln des Sprach- und Störschalls auf der einen Seite und der Verständlichkeit auf der anderen Seite (p < 0,001). Die gemittelten Verständlichkeitsquoten und zugehörigen 95%-KI sowie die Häufigkeitsverteilungen wurden tabellarisch und grafisch dargestellt.

Schlussfolgerung

Die Verständlichkeitskurve des FBE‑S ist im Vergleich zur Normkurve des FBE nach rechts verschoben. Die gemittelte Kurve des FBE‑S erreicht bei einem Schalldruckpegel von 70 dB und einem Störschalldruckpegel von 65 dB den Sättigungsbereich von 90 % Verständlichkeit (zum Vergleich: Der Sättigungspunkt von 100 % Verständlichkeit liegt beim FBE ohne Störschall bei 55 dB). Durch die hier vorgestellte Verständlichkeitskurve lassen sich individuelle Messergebnisse ohne und mit Hörgeräten besser interpretieren. Künftig sollte der Hörgewinn für Hörgeräte möglicherweise bei niedrigeren Schalldruckpegeln erfolgen als heute.

[Characterization of a closed-set logatome test : Documentation of audiometric data: discrimination function and reproducibility]

BACKGROUND

Logatomes, nonsensical combinations of consonants and vowels, are suitable for a precise capture and analysis of individual phonemes as fundamental modules of speech in audiometric diagnostics.

OBJECTIVE

The aim of this prospective study was to capture the audiometric characteristics of a closed-set logatome test. The slope of the discrimination function at the speech reception threshold (SRT) and the reproducibility were analyzed.

MATERIAL AND METHODS

A set of 102 intensity varied and randomized logatomes were presented in the form of consonant-vowel-consonant to 25 hearing unimpaired adults. The measurements were performed in a free field setting and were each repeated after a 2-week interval. The subjects were requested to repeat the heard logatome in a closed response test of 10 items per sound item on a touchscreen.

RESULTS

The slope of the mean discrimination function at the SRT was on average 4%/dB; however, the mean discrimination function slope was steeper for the initial consonant than for the final one. The differences of the test and retest results at the SRT showed a standard deviation of 13% for consonants. These differences were normally distributed. There were no significant differences between test and retest.

CONCLUSION

The slope of the discrimination function at the SRT appeared to be shallow but was comparable to established word tests. Finally, there was no evidence of a learning effect in the retest, which emphasizes the low redundancy of the speech material and makes it an attractive complementary option to routine audiometric diagnostics.

Direct Acoustic Cochlear Implants Lead to an Improved Speech Perception Gap Compared to Conventional Hearing Aid

OBJECTIVES

The objectives of this study was to evaluate the aided speech perception in quiet of direct acoustic cochlear implant (DACI) patients and the speech perception gap in comparison with hearing aid users.

STUDY DESIGN

Retrospective comparative study.

SETTING

Tertiary referral center.

PATIENTS

Adults with moderate-to-severe mixed hearing loss who have been implanted with a DACI and fitted with a processor for at least 6 months.

INTERVENTION(S)

Comparison of aided monosyllabic word scores and speech perception gap of 59 DACI-implanted ears speech perception gap with published data on 208 ears aided with a conventional hearing aid (HA) divided into four different hearing loss groups between 35 and 75 dB HL.

MAIN OUTCOME MEASURE(S)

Aided monosyllabic word score, predicted maximum monosyllabic word recognition score (PBmax) and speech perception gap.

RESULTS

In terms of aided speech perception, DACI patients with cochlear reserves between 45 and 65 dB HL have a significant advantage compared with conventional HA users. A speech perception gap of 11% points for DACI and 21% points for conventional HAs were determined and an approximation of PBmax is achieved by 52% of the DACI patients compared with only 36% of the HA users.

CONCLUSIONS

For patients with moderate-to-severe inner ear hearing loss between 45 and 65 dB HL, better speech perception in quiet is obtained with the DACI system. Compared with conventional hearing aids, speech performance with the DACI is closer to the maximally possibly score PBmax.

[The adaptive Freiburg monosyllabic test in noise : Development of a procedure and comparison of the results with the Oldenburg sentence test]

BACKGROUND

Whereas sentence tests are commonly performed using an adaptive procedure, this method has not yet been transferred to the Freiburg monosyllabic speech test, the most important word test. When using different procedures, a comparison of results between sentence and word tests is not possible. Therefore, an adaptive procedure which has proven itself in sentence tests was transferred to the Freiburg monosyllabic test in noise. The results of the new procedure were compared to the standard of sentence tests, i.e., the Oldenburg sentence test.

METHODS

The adaptive Freiburg monosyllabic speech test and the Oldenburg sentence test were applied in 40 otologically normal subjects in a randomized order. Results were analyzed with respect to time requirements, possible gender differences, the influence of test order, and correlation of test results.

RESULTS

The time required for the adaptive Freiburg monosyllabic speech test was significantly higher than for the Oldenburg sentence test. No significant impact of gender or test order could be shown. The mean signal-to-noise ratio for 50% speech discrimination of the Oldenburg sentence test was significantly smaller than for the adaptive Freiburg monosyllabic speech test. No correlation could be shown between the results of the two tests CONCLUSION: The Freiburg monosyllabic test can not only be used for quantifying discrimination loss in percentage terms, but also to measure the 50% speech recognition threshold with an adaptive algorithm. However, the procedure of the adaptive Freiburg monosyllabic test is more time consuming than that of the Oldenburg sentence test. Concerning a possible missing correlation between the results for 50% speech discrimination, further studies with hearing-impaired persons are needed.

[Speech audiometry and data logging in CI patients : Implications for adequate test levels. German version]

BACKGROUND

As part of postoperative cochlear implant (CI) diagnostics, speech comprehension tests are performed to monitor audiological outcome. In recent years, a trend toward improved suprathreshold speech intelligibility in quiet and an extension of intelligibility to softer sounds has been observed. Parallel to audiometric data, analysis of the patients' acoustic environment can take place by means of data logging in modern CI systems.

OBJECTIVES

Which test levels reflect the individual listening environment in a relevant manner and how can these be reflected in a clinical audiometric setting?

PATIENTS AND METHODS

In a retrospective analysis, data logs of 263 adult CI patients were evaluated for sound level and the listening situation (quiet, speech in quiet, noise, speech in noise, music, and wind). Additionally, monosyllabic word comprehension in quiet was analyzed in experienced CI users at presentation levels of 40-80 dB.

RESULTS

For the sound level in the acoustic environment of postlingually deafened adult CI users, data logging shows a maximum occurrence of speech signals in the range 50-59 dB. This demonstrates the relevance of everyday speech comprehension at levels below 60 dB.

CONCLUSIONS

Individual optimization of speech intelligibility with a CI speech processor should not be performed in the range of 65-70 dB only, but also at lower levels. Measurements at 50 dB currently seem to be a useful addition.

Current audiological diagnostics

Today’s audiological functional diagnostics is based on a variety of hearing tests, whose large number takes account of the variety of malfunctions of a complex sensory organ system and the necessity to examine it in a differentiated manner and at any age of life. The objective is to identify nature and origin of the hearing loss and to quantify its extent as far as necessary to dispose of the information needed to initiate the adequate medical (conservative or operational) treatment or the provision with technical hearing aids or prostheses. Moreover, audiometry provides the basis for the assessment of impairment and handicap as well as for the calculation of the degree of disability. In the present overview, the current state of the method inventory available for practical use is described, starting from basic diagnostics over to complex special techniques. The presentation is systematically grouped in subjective procedures, based on psychoacoustic exploration, and objective methods, based on physical measurements: preliminary hearing tests, pure tone threshold, suprathreshold processing of sound intensity, directional hearing, speech understanding in quiet and in noise, dichotic hearing, tympanogram, acoustic reflex, otoacoustic emissions and auditory evoked potentials. Apart from a few still existing gaps, this method inventory covers the whole spectrum of all clinically relevant functional deficits of the auditory system.

[The Freiburg speech intelligibility test : A pillar of speech audiometry in German-speaking countries]

The Freiburg speech intelligibility test according to DIN 45621 was introduced around 60 years ago. For decades, and still today, the Freiburg test has been a standard whose relevance extends far beyond pure audiometry. It is used primarily to determine the speech perception threshold (based on two-digit numbers) and the ability to discriminate speech at suprathreshold presentation levels (based on monosyllabic nouns). Moreover, it is a measure of the degree of disability, the requirement for and success of technical hearing aids (auxiliaries directives), and the compensation for disability and handicap (Königstein recommendation). In differential audiological diagnostics, the Freiburg test contributes to the distinction between low- and high-frequency hearing loss, as well as to identification of conductive, sensory, neural, and central disorders. Currently, the phonemic and perceptual balance of the monosyllabic test lists is subject to critical discussions. Obvious deficiencies exist for testing speech recognition in noise. In this respect, alternatives such as sentence or rhyme tests in closed-answer inventories are discussed.

[Evaluation of the perceptual equivalence of test lists in the Freiburg monosyllabic speech test]

BACKGROUND

In the past, the perceptual balance of test lists for the Freiburg monosyllabic speech test (FBE) was frequently evaluated without producing consistent results. Until now, the studies used very diverse methods and did not accurately follow the standardized specifications. In this study, therefore, the perceptual equivalence of test lists was verified with a large group of participants according to the standard ISO EN 8253-3.

METHODS

A total of 160  suitable otologically normal subjects were recruited at two institutions, each of whom listened to all test lists of the FBE using predefined measurement conditions. The subjects were divided in three groups depending on the transducer used for test list presentation (headphones "HDA 200" and "TDH 39", as well as free-field loudspeaker, "FF"). Lists that deviated were identified using the approaches specified in the standard.

RESULTS

The reference curve for FBE was not met by any group. While the "HDA 200" group indicated 4.6 dB lower thresholds, results for the "TDH 39" and "FF" groups showed 1.2 and 2.5 dB higher thresholds, respectively. For an average speech recognition score of 44.3 %, test lists 5, 11, 12, and 15 lay outside the calculated tolerance range of 4.5 to -4.4 percent points. The same lists also deviated when calculating discrimination functions and therefore do not fulfill the criteria for perceptual equivalence.

DISCUSSION

In the future, lists identified as deviating from the norm should not be used. The results of this study only partly agree with results from former studies.