Thomas Hocke

Investigation of a matrix sentence test in noise: Reproducibility and discrimination function in cochlear implant patients

Abstract Objective: The aim of this study was to describe common properties (reproducibility, discrimination function, and its steepness) of matrix tests used for cochlear implant (CI) users and to obtain data for the German-language version matrix test, the Oldenburg sentence test (OLSA), presented in noise. Design: The speech reception thresholds (SRT) in noise were measured by means of an adaptive test procedure, and by measurement at various signal-to-noise ratios to determine the course of the entire discrimination function per subject. Study sample: The measurements were performed on 38 CI users fitted with a Cochlear™ Freedom® or a Cochlear™ Nucleus® 5 CI system. Results: The test–retest reproducibility showed a significant dependence on the SRT in noise. For the better performers, the test-retest difference was found to be smaller, while for the poorer performers the difference increased. For the better performers, the slope of the discrimination function at SRT (s50) was comparable to that for individuals with normal hearing, while for the poorer performers the s50 tended to be significantly reduced. Conclusions: As the CI users differed significantly in their SRT and their s50, a unified discrimination function for CI users must not be used. Further tailoring of the procedure may be required, especially for poorer CI performers.

Audiometry-Based Screening Procedure for Cochlear Implant Candidacy.

Objective This study defines a screening procedure for cochlear implant (CI) candidacy in hearing aid users by using simple audiometric measures. Methods Within this retrospective study, hearing aid performance and audiometric measures in 185 subjects (318 ears) were analyzed. By means of a linear Naive Bayes classifier, the pure-tone average and the maximum monosyllabic score (PBmax) were used to predict the aided monosyllabic word score and CI candidacy. Results The two parameters PBmax and four-frequency hearing threshold average can be used to predict speech perception with hearing aids with reasonable accuracy for screening purposes. The classification has a sensitivity of 87% and a specificity of 91%. The classification can be represented by a simple linear formula. Conclusion CI candidacy can be predicted based on commonly used audiometric measures. Cochlear implant candidacy may be considered if the difference between the average pure-tone threshold (in decibels) and PBmax (in percent) exceeds 8.

Sprachverstehen mit Hörgeräten in Abhängigkeit vom Tongehör

BACKGROUND AND AIM Speech perception is the most important social task of the auditory system. Consequently, speech audiometry is essential to evaluate hearing aid benefit. The aim of the study was to describe the correlation between pure-tone hearing loss and speech perception. In particular, pure-tone audiogram, speech audiogram, and speech perception with hearing aids were compared. MATERIALS AND METHODS In a retrospective study, 102 hearing aid users with bilateral sensorineural hearing loss were included. Pure-tone loss (PTA) was correlated to monosyllabic perception at 65 dB with hearing aid and with maximum monosyllabic perception with headphones. RESULTS Speech perception as a function of hearing loss can be represented by a sigmoid function. However, for higher degrees of hearing loss, substantial deviations are observed. Maximum monosyllabic perception with headphones is usually not achieved with hearing aids at standard speech levels of 65 dB. CONCLUSION For larger groups, average pure-tone hearing loss and speech perception correlate significantly. However, prognosis for individuals is not possible. In particular for higher degrees of hearing loss substantial deviations could be observed. Speech performance with hearing aids cannot be predicted sufficiently from speech audiograms. Above the age of 80, speech perception is significantly worse.

Der Einfluss des Alters bei der Evaluierung des funktionellen Hörgerätenutzens mittels Sprachaudiometrie

BACKGROUND AND AIM Hearing loss is one of the most common disabilities in the elderly. The aim of this study was to investigate the relationship between pure-tone hearing loss and maximum monosyllabic perception and speech perception with hearing aids. The focus of the investigation was elderly patients. MATERIALS AND METHODS In this prospective study, 188 patients with sensorineural hearing loss were included. The pure-tone audiogram (4FPTA), the Freiburg speech intelligibility test with headphones and the word recognition score with hearing aids at 65 dB SPL were measured and evaluated. RESULTS An increasing age was associated with higher discrepancy between the maximum speech perception and speech understanding with hearing aids. The mean difference between maximum monosyllabic perception and speech perception with hearing aids is about 20% in the elderly population. CONCLUSION The intended goal of hearing aid prescription, the match between maximum monosyllabic perception and word recognition score with hearing aids within 5 to 10%, is not achieved in the elderly population.

Intraoperative findings on ECAP-measurement: Normal or special case?

Abstract Objective: This study aimed to investigate the measurability and threshold level of electrically evoked compound action potentials (ECAPs) in order to provide a baseline for the development of diagnostic references to support aftercare procedures. Design: In this retrospective study, cochlear implant patients were grouped according to the electrode array type and preoperative diagnostic findings from radiological imaging. ECAP measurements were performed intraoperatively on 22 electrodes for each patient resulting in two comparisons: (1) normal vs. pathological findings based on imaging with same electrode array, (2) perimodiolar electrode vs. straight electrode array within the normal group. Study sample: The study sample consisted of 218 ears with a Nucleus® implant. Results: In the group with normal radiological imaging, the percentage of measurable ECAPs was higher than in the pathological group. The ECAP thresholds on 21 electrodes were significantly different between the two groups. Furthermore the thresholds were significantly lower for basal electrodes mainly for the two different electrode types. Conclusion: The pathological changes in the inner ear, the type of electrode array, and the electrode position affect the ECAP threshold. Further consideration suggests that a receiver operating characteristic curve can be derived from the results.

The age effect in evaluation of hearing aid benefits by speech audiometry

BACKGROUND AND AIM Hearing loss is one of the most common disabilities in the elderly. The aim of this study was to investigate the relationship between pure-tone hearing loss and maximum monosyllabic perception and speech perception with hearing aids. The focus of the investigation was elderly patients. MATERIALS AND METHODS In this prospective study, 188 patients with sensorineural hearing loss were included. The pure-tone audiogram (4FPTA), the Freiburg speech intelligibility test with headphones and the word recognition score with hearing aids at 65 dB SPL were measured and evaluated. RESULTS An increasing age was associated with higher discrepancy between the maximum speech perception and speech understanding with hearing aids. The mean difference between maximum monosyllabic perception and speech perception with hearing aids is about 20% in the elderly population. CONCLUSION The intended goal of hearing aid prescription, the match between maximum monosyllabic perception and word recognition score with hearing aids within 5 to 10%, is not achieved in the elderly population.

[Speech perception with hearing aids in comparison to pure-tone hearing loss].

BACKGROUND AND AIM Speech perception is the most important social task of the auditory system. Consequently, speech audiometry is essential to evaluate hearing aid benefit. The aim of the study was to describe the correlation between pure-tone hearing loss and speech perception. In particular, pure-tone audiogram, speech audiogram, and speech perception with hearing aids were compared. MATERIALS AND METHODS In a retrospective study, 102 hearing aid users with bilateral sensorineural hearing loss were included. Pure-tone loss (PTA) was correlated to monosyllabic perception at 65 dB with hearing aid and with maximum monosyllabic perception with headphones. RESULTS Speech perception as a function of hearing loss can be represented by a sigmoid function. However, for higher degrees of hearing loss, substantial deviations are observed. Maximum monosyllabic perception with headphones is usually not achieved with hearing aids at standard speech levels of 65 dB. CONCLUSION For larger groups, average pure-tone hearing loss and speech perception correlate significantly. However, prognosis for individuals is not possible. In particular for higher degrees of hearing loss substantial deviations could be observed. Speech performance with hearing aids cannot be predicted sufficiently from speech audiograms. Above the age of 80, speech perception is significantly worse.

Bimodal benefit for cochlear implant listeners with different grades of hearing loss in the opposite ear

Abstract Objective: To determine speech perception in quiet and noise of adult cochlear implant listeners retaining a hearing aid contralaterally. Second, to investigate the influence of contralateral hearing thresholds and speech perception on bimodal hearing. Patients and methods: Sentence recognition with hearing aid alone, cochlear implant alone and bimodally at 6 months after cochlear implantation were assessed in 148 postlingually deafened adults. Data were analyzed for bimodal summation using measures of speech perception in quiet and in noise. Results: Most of the subjects showed improved sentence recognition in quiet and in noise in the bimodal condition compared to the hearing aid-only or cochlear implant-only mode. The large variability of bimodal benefit in quiet can be partially explained by the degree of pure tone loss. Also, subjects with better hearing on the acoustic side experience significant benefit from the additional electrical input. Conclusions: Bimodal summation shows different characteristics in quiet and noise. Bimodal benefit in quiet depends on hearing thresholds at higher frequencies as well as in the lower- and middle-frequency ranges. For the bimodal benefit in noise, no correlation with hearing threshold in any frequency range was found.

Contralateral electrically-evoked suppression of transient evoked otoacoustic emissions in single-sided deaf patients

HighlightsContralateral suppression of TEOAE by electrically stimulation via cochlear implant.Contralateral electrical stimulation leads to a change of TEOAE amplitudes in the normal‐hearing ear in some CI‐SSD recipients.The normal‐hearing ear can remain subject to the medial cochlear efferent mechanisms at the brainstem level with electrical stimulation to the deaf ear.

Excitation characteristic of a bipolar stimulus for broadband stimulation in measurements of electrically evoked auditory potentials

OBJECTIVE The aim of this study was to determine the optimum electrical stimulation mode for the measurement of electrically evoked potentials. To quantify the broadband excitation electrically evoked compound action potentials were recorded in cochlear implant recipients. The full width half maximum was determined for spread of excitation along the electrode array. DESIGN Prospective clinical study. STUDY SAMPLE The study sample consisted of 20 adult cochlear implant users. RESULTS The applied alternating, intracochlear stimulation mode leads to neural excitation along approximately 80% of the length of the electrode array. The median of the full width at half maximum values covered the range of 18 electrodes on the implant array. CONCLUSION The bipolar, alternating, and intracochlear stimulation mode would provide a sufficient, broadband excitation of the spiral ganglion to measure electrically evoked auditory potentials.