Inga Holube

Prävalenz von Schwerhörigkeit im Nordwesten Deutschlands

BACKGROUNDnA pure-tone average of 0.5, 1, 2, and 4 kHz in the better ear (PTA-4) is the international standard criterion set by the World Health Organization (WHO) to describe hearing loss. Presently, there are no epidemiological data on hearing loss in Germany based on this criterion.nnnMETHODSnA representative sample of adults from Oldenburg and Emden were invited for a hearing assessment. This article analyzes the association between hearing loss and age, sex, noise, occupation, and educational level. Age- and sex-specific prevalence rates following the WHO classification are compared with international findings.nnnRESULTSnAccording to the WHO classification, the prevalence of hearing impairment in the study cohort (n=1,866) is approx. 16%. In men, who more commonly work in noisy jobs, a higher prevalence rate is observed than in women of the same age. Nevertheless, sex differences in the present study are smaller than those reported in most international studies. PTA-4 is approximately the same for men and women when effects of occupational noise are controlled, but differences in prevalence between occupational areas are still significant.nnnCONCLUSIONnCompared with international findings, age-specific prevalence rates in HÖRSTAT are low. In the synopsis of epidemiological studies of the past 25 years, a trend toward decreasing prevalence in middle and higher age groups can be observed.ZusammenfassungHintergrundDer mittlere Luftleitungshörverlust bei 0,5, 1, 2 und 4xa0kHz („pure tone average“, PTA-4) im besseren Ohr ist das international anerkannte Kriterium der Weltgesundheitsorganisation (WHO) zur Beschreibung des Hörvermögens. Zurzeit gibt es keine epidemiologischen Daten zum Hörverlust in der deutschen Bevölkerung, in der dieses Kriterium verwendet wird.MethodenEine populationstypische Stichprobe erwachsener Personen aus Oldenburg und Emden wurde zu einer eingeladen. Analysiert wird der Zusammenhang von Hörverlusten mit Alter, Geschlecht, Lärm, Berufsbereich und schulischer Bildung. Die alters- und geschlechtsspezifische Prävalenz nach WHO wird mit internationalen Studienergebnissen verglichen.ErgebnisseDie Prävalenz von Schwerhörigkeit nach der WHO-Klassifikation lag bei den Studienteilnehmern (nu2009=u20091866) bei etwa 16u2009%. Bei Männern, die häufiger in lärmbelasteten Berufsbereichen tätig waren, wurde eine höhere Prävalenz als bei Frauen gleichen Alters beobachtet. Der Unterschied zwischen den Geschlechtern ist jedoch geringer als in internationalen Vergleichsstudien. Bei Berücksichtigung beruflicher Lärmexposition gleichen sich beide Geschlechter im PTA-4, signifikante Unterschiede zwischen verschiedenen Berufsbereichen aber bleiben erhalten.SchlussfolgerungIm internationalen Vergleich liegt die altersabhängige Prävalenz in HÖRSTAT niedrig. Aus den Studienergebnissen der vergangenen 25 Jahre ist eine Tendenz zu abnehmender Prävalenz von Schwerhörigkeit im mittleren bis oberen Altersbereich zu beobachten.AbstractBackgroundA pure-tone average of 0.5, 1, 2, and 4xa0kHz in the better ear (PTA-4) is the international standard criterion set by the World Health Organization (WHO) to describe hearing loss. Presently, there are no epidemiological data on hearing loss in Germany based on this criterion.MethodsA representative sample of adults from Oldenburg and Emden were invited for a hearing assessment. This article analyzes the association between hearing loss and age, sex, noise, occupation, and educational level. Age- and sex-specific prevalence rates following the WHO classification are compared with international findings.ResultsAccording to the WHO classification, the prevalence of hearing impairment in the study cohort (nu2009=u20091,866) is approx. 16u2009%. In men, who more commonly work in noisy jobs, a higher prevalence rate is observed than in women of the same age. Nevertheless, sex differences in the present study are smaller than those reported in most international studies. PTA-4 is approximately the same for men and women when effects of occupational noise are controlled, but differences in prevalence between occupational areas are still significant.ConclusionCompared with international findings, age-specific prevalence rates in HÖRSTAT are low. In the synopsis of epidemiological studies of the past 25xa0years, a trend toward decreasing prevalence in middle and higher age groups can be observed.

Measurement and prediction of the acceptable noise level for single-microphone noise reduction algorithms

Abstract Objective: To measure the acceptable noise level (ANL) with and without noise reduction algorithms (NRAs), and to predict ΔANL, i.e. the difference in acceptable noise level with and without NRAs. Design: The ANL test was applied to three NRAs. Furthermore, the measured ΔANL was predicted using several methods based on either the calculation of the signal-to-noise ratio or correlation methods of the processed signals with an unprocessed reference signal. Study sample: Ten normal-hearing and eleven hearing-impaired subjects accomplished the ANL test. Results: In general, the ANL test could determine an increased acceptance of noise with some NRAs. However, great inter-individual differences also resulted that were attributed to audible distortions when an NRA was used. Prediction of the mean measured DANL was possible, but individual prediction of DANL failed due to inter-individual differences. Mean DANL was predicted more accurately for hearing-impaired subjects when individual hearing loss was taken into account. Conclusions: The ANL test is a suitable tool for measuring the advantage of one NRA. A prediction of the measured individual ΔANL failed. However, mean DANL could be predicted with some methods. Furthermore, the individual hearing loss should be taken into account for a more accurate prediction for hearing-impaired subjects.

A Phoneme Perception Test Method for High-Frequency Hearing Aid Fitting.

BACKGROUNDnOutcomes with hearing aids (HAs) can be assessed using various speech tests, but many tests are not sensitive to changes in high-frequency audibility.nnnPURPOSEnA Phoneme Perception Test (PPT), designed for the phonemes /s/ and /ʃ/, has been developed to investigate whether detection and recognition tasks are able to measure individual differences in phoneme audibility and recognition for various hearing instrument settings. These capabilities were studied using two different fricative stimulus materials. The first set of materials preserves natural low-level sound components in the low- and mid-frequency ranges (LF set); the second set of materials attempts to limit the audibility to high-frequency fricative noise (nLF set). To study the effect on phoneme detection and recognition when auditory representations of /s/ and /ʃ/ are modified, a too strong nonlinear frequency compression (NLFC) setting was applied.nnnRESEARCH DESIGNnRepeated measure design was used under several different conditions.nnnSTUDY SAMPLEnA total of 31 hearing-impaired individuals participated in this study. Of the 31 participants, 10 individuals did not own HAs but were provided with them during the study and 21 individuals owned HAs and were experienced users. All participants had a symmetrical sensorineural hearing loss.nnnDATA COLLECTION AND ANALYSISnThe present study applied a phoneme detection test and a recognition test with two different stimulus sets under different amplification conditions. The statistical analysis focused on the capability of the PPT to measure the effect on audibility and perception of high-frequency information with and without HAs, and between HAs with two different NLFC settings (default and too strong).nnnRESULTSnDetection thresholds (DTs) and recognition thresholds (RTs) were compared with respective audiometric thresholds in the free field for all available conditions. Significant differences in thresholds between LF and nLF stimuli were observed. The thresholds for nLF stimuli showed higher correlation to the corresponding audiometric thresholds than the thresholds for LF stimuli. The difference in thresholds for unaided and aided conditions was larger for the stimulus set nLF than for the stimulus set LF. Also, thresholds were similar in both aided conditions for stimulus set LF, whereas a large difference between amplifications was observed for the stimulus set nLF. When NLFC was set too strong, DTs and RTs differed significantly for /s/.nnnCONCLUSIONSnThe findings from this study strongly suggest that measuring DTs and RTs with the stimulus set nLF is beneficial and useful to quantify the effects of HAs and NLFC on high-frequency speech cues for detection and recognition tasks. The findings also suggest that both tests are necessary because they assess audibility as well as recognition abilities, particularly as they relate to speech modification algorithms. The experiments conducted in this study did not allow for any acclimatization of the participants to increased high-frequency gain or NLFC. Further investigations should therefore examine the impact on DTs and RTs in the PPT as well as the contrasting effects of strong setting of NLFC to DTs and RTs because of (re)learning of modified auditory representations of /s/ and /ʃ/ as caused by NLFC.

Hearing-Aid Technology

Within the last 15 years, hearing instruments have strongly improved due to the application of modern technologies. This chapter provides a look at the possibilities and restrictions of the technologies used and at the signal-processing algorithms available today for the most advanced commercial hearing instruments. Due to ongoing development in semi-conductors the application of even more complex algorithms is expected for the near future. The first part of this chapter focuses on the different designs and chip technologies seen with today’s hearing instrument. Consequently, signal-processing algorithms are reviewed which are applied in digital hearing instruments. Finally, we deal with the components of hearing instruments and with methods for fitting the instruments to the individual’s hearing impairment.

Open Versus Closed Hearing-Aid Fittings: A Literature Review of Both Fitting Approaches:

One of the main issues in hearing-aid fittings is the abnormal perception of the user’s own voice as too loud, “boomy,” or “hollow.” This phenomenon known as the occlusion effect be reduced by large vents in the earmolds or by open-fit hearing aids. This review provides an overview of publications related to open and closed hearing-aid fittings. First, the occlusion effect and its consequences for perception while using hearing aids are described. Then, the advantages and disadvantages of open compared with closed fittings and their impact on the fitting process are addressed. The advantages include less occlusion, improved own-voice perception and sound quality, and increased localization performance. The disadvantages associated with open-fit hearing aids include reduced benefits of directional microphones and noise reduction, as well as less compression and less available gain before feedback. The final part of this review addresses the need for new approaches to combine the advantages of open and closed hearing-aid fittings.

Subjective Listening Effort and Electrodermal Activity in Listening Situations with Reverberation and Noise.

Disturbing factors like reverberation or ambient noise can impair speech recognition and raise the listening effort needed for successful communication in daily life. Situations with high listening effort are thought to result in increased stress for the listener. The aim of this study was to explore possible measures to determine listening effort in situations with varying background noise and reverberation. For this purpose, subjective ratings of listening effort, speech recognition, and stress level, together with the electrodermal activity as a measure of the autonomic stress reaction, were investigated. It was expected that the electrodermal activity would show different stress levels in different acoustic situations and might serve as an alternative to subjective ratings. Ten young normal-hearing and 17 elderly hearing-impaired subjects listened to sentences from the Oldenburg sentence test either with stationary background noise or with reverberation. Four listening situations were generated, an easy and a hard one for each of the two disturbing factors, which were related to each other by the Speech Transmission Index. The easy situation resulted in 100% and the hard situation resulted in 30 to 80% speech recognition. The results of the subjective ratings showed significant differences between the easy and the hard listening situations in both subject groups. Two methods of analyzing the electrodermal activity values revealed similar, but nonsignificant trends. Significant correlations between subjective ratings and physiological electrodermal activity data were observed for normal-hearing subjects in the noise situation.

Perceived listening effort and speech intelligibility in reverberation and noise for hearing-impaired listeners

Abstract Objective: The purpose of this study was to assess perceived listening effort and speech intelligibility in reverberant and noisy conditions for hearing-impaired listeners for conditions that are similar according to the speech transmission index (STI). Design: Scaled listening effort was measured in four different conditions at five different STI generated using various relative contributions of noise and reverberant interferences. Intelligibility was measured for a subset of conditions. Study sample: Twenty mildly to moderately hearing-impaired listeners. Results: In general, listening effort decreased and speech intelligibility increased with increasing STI. For simulated impulse responses consisting of white Gaussian noise exponentially decaying in time, a good agreement between conditions of different relative contributions of noise and reverberation was found. For real impulse responses, the STI slightly overestimated the effect of reverberation on the perceived listening effort and underestimated its effect on speech intelligibility. Including the average hearing loss in the calculation of the STI led to a better agreement between STI predictions and subjective data. Conclusion: Speech intelligibility and listening effort provide complementary tools to evaluate speech perception over a broad range of acoustic scenarios. In addition, when incorporating hearing loss information the STI provides a rough prediction of listening effort in these acoustic scenarios.

Prävalenz von Schwerhörigkeit in Nord- und Süddeutschland

BACKGROUNDnThe HÖRSTAT study conducted in Northwest Germany yielded hearing impairment in approximately 16% of adults according to the World Health Organization (WHO) criterion. However, the robustness of extrapolations on axa0national level might be questioned, as the epidemiological data were collected on axa0regional level.nnnMETHODSnIndependently from HÖRSTAT, the Hearing in Germany study examined adult hearing in Aalen, axa0town located in Southwest Germany. Both cross-sectional studies were based on stratified random samples from the general population. Pure-tone average at 0.5, 1, 2, and 4u2009kHz (PTA4), the prevalence of hearing impairment (WHO criterion: PTA4 in the better ear >25u2009dBu2009HL), and hearing aid provision were compared. Data from the Aalen study and HÖRSTAT were pooled (nxa0= 3105) to extrapolate the prevalence and degree of hearing impairment for the years 2015, 2020, and 2025.nnnRESULTSnBoth studies show very similar results for PTA4. Weighted for official population statistics, the prevalence of hearing impairment according to the WHO criterion is 16.2% among adults, affecting 11.1xa0million persons in Germany. Due to demographic changes, the prevalence is expected to increase in the medium term by around 1% per 5‑year period. With axa0similar degree of hearing loss, hearing aid provision differs from place to place.nnnCONCLUSIONnAdjusted for gender and age to the European Standard Population (ESP), the prevalence of hearing impairment observed both in HÖRSTAT and the Aalen sample is considerably lower than reported for international studies. Since the analysis refers to cross-sectional data only, possible cohort effects are not considered in the prevalence projection.ZusammenfassungHintergrundDie Untersuchung HÖRSTAT im Nordwesten Deutschlands ergab, dass rund 16u2009% der Erwachsenen nach dem Kriterium der Weltgesundheitsorganisation (WHO) schwerhörig sind. Die Belastbarkeit landesweiter Hochrechnungen aus regional durchgeführten epidemiologischen Untersuchungen kann indes infrage gestellt werden.MethodenDie Studie „Wie hört Deutschland?“ wurde unabhängig von HÖRSTAT im südwestdeutschen Aalen durchgeführt. Beide Querschnittstudien basierten auf stratifizierten Zufallsstichproben aus der Allgemeinbevölkerung. Der mittlere Tonhörverlust bei 500u2009Hz, 1, 2xa0und 4u2009kHz („pure-tone average“, PTA4), die Prävalenz von Schwerhörigkeit (WHO-Kriterium: PTA4 des besseren Ohrs >25u2009dBu2009HL) und die Versorgung mit Hörgeräten wurden verglichen. Die Daten aus Aalen und HÖRSTAT wurden zusammengeführt (nxa0= 3105), um die Prävalenz von Schwerhörigkeit in ihrer graduellen Ausprägung für die Jahre 2015, 2020 und 2025 hochzurechnen.ErgebnisseDie beobachteten mittleren Hörverluste beider Studien stimmen sehr gut überein. Gewichtet nach Maßgabe der Bevölkerungsstatistik sind 16,2u2009% der Erwachsenen in Deutschland (11,1xa0Mio.) nach dem WHO-Kriterium schwerhörig. Aufgrund der demographischen Entwicklung ist mittelfristig ein Prävalenzanstieg von 1u2009% pro Jahrfünft zu erwarten. Bei vergleichbarem Hörverlust ist die Versorgung mit Hörgeräten in den Studienorten unterschiedlich.SchlussfolgerungBei Adjustierung der Geschlechts- und Altersverteilung auf die europäische Standardpopulation (ESP) liegt die Prävalenz von Schwerhörigkeit in HÖRSTAT ebenso wie in der Aalener Untersuchung deutlich niedriger als in internationalen Vergleichsstudien. Die Analyse basiert ausschließlich auf Querschnittsdaten. Mögliche Kohorteneffekte sind in der Vorausberechnung der Prävalenz deshalb nicht berücksichtigt.AbstractBackgroundThe HÖRSTAT study conducted in Northwest Germany yielded hearing impairment in approximately 16% of adults according to the World Health Organization (WHO) criterion. However, the robustness of extrapolations on axa0national level might be questioned, as the epidemiological data were collected on axa0regional level.MethodsIndependently from HÖRSTAT, the “Hearing in Germany” study examined adult hearing in Aalen, axa0town located in Southwest Germany. Both cross-sectional studies were based on stratified random samples from the general population. Pure-tone average at 0.5, 1, 2, and 4u2009kHz (PTA4), the prevalence of hearing impairment (WHO criterion: PTA4 in the better ear >25u2009dBu2009HL), and hearing aid provision were compared. Data from the Aalen study and HÖRSTAT were pooled (nxa0= 3105) to extrapolate the prevalence and degree of hearing impairment for the years 2015, 2020, and 2025.ResultsBoth studies show very similar results for PTA4. Weighted for official population statistics, the prevalence of hearing impairment according to the WHO criterion is 16.2% among adults, affecting 11.1xa0million persons in Germany. Due to demographic changes, the prevalence is expected to increase in the medium term by around 1% per 5‑year period. With axa0similar degree of hearing loss, hearing aid provision differs from place to place.ConclusionAdjusted for gender and age to the European Standard Population (ESP), the prevalence of hearing impairment observed both in HÖRSTAT and the Aalen sample is considerably lower than reported for international studies. Since the analysis refers to cross-sectional data only, possible cohort effects are not considered in the prevalence projection.

Social inequalities in pure-tone hearing assessed using occupational stratification schemes

Abstract Objective: The objective of this study is to analyse the performance of two occupational stratification approaches and the impact of social position on adult hearing. Design: The prevalence of hearing impairment, pure-tone averages (PTA) and prevalence ratios (PR) for relative hearing loss, which focuses on the position of one’s PTA in the age- and gender-specific distribution, were compared in groups defined by ISCO Skill Level and the International Socio-Economic Index (ISEI). Study sample: About 1571 subjects aged 30–89, including 677 highly screened adults, from the cross-sectional study HÖRSTAT. Results: ISCO Skill Level and ISEI yielded qualitatively the same results. The prevalence difference between the socially least and most advantaged group ranges between 10 and 16%, varying with the scheme applied. Low- and high-frequency PTA and PR for relative hearing loss confirm the gradient. Screening reduced, but did not negate the social differences. The prevalence difference dropped to 6–7% in the otologically normal subsample. Conclusions: Social groups defined by hierarchical, occupational measures differ in their pure-tone hearing, even if the main risk factors are controlled for. This underlines the need for population-based sampling, the relevance of reporting the study group’s social composition and the importance of advancing the discussion on appropriate social measures in hearing research.

Relation Between Listening Effort and Speech Intelligibility in Noise

PurposenSubjective ratings of listening effort might be applicable to estimate hearing difficulties at positive signal-to-noise ratios (SNRs) at which speech intelligibility scores are near 100%. Hence, ratings of listening effort were compared with speech intelligibility scores at different SNRs, and the benefit of hearing aids was evaluated.nnnMethodnTwo groups of listeners, 1 with normal hearing and 1 with hearing impairment, performed adaptive speech intelligibility and adaptive listening effort tests (Adaptive Categorical Listening Effort Scaling; Krueger, Schulte, Brand, & Holube, 2017) with sentences of the Oldenburg Sentence Test (Wagener, Brand, & Kollmeier, 1999a, 1999b; Wagener, Kühnel, & Kollmeier, 1999) in 4 different maskers. Model functions were fitted to the data to estimate the speech reception threshold and listening effort ratings for extreme effort and no effort.nnnResultsnListeners with hearing impairment showed higher rated listening effort compared with listeners with normal hearing. For listeners with hearing impairment, the rating extreme effort, which corresponds to negative SNRs, was more correlated to the speech reception threshold than the rating no effort, which corresponds to positive SNRs. A benefit of hearing aids on speech intelligibility was only verifiable at negative SNRs, whereas the effect on listening effort showed high individual differences mainly at positive SNRs.nnnConclusionnThe adaptive procedure for rating subjective listening effort yields information beyond using speech intelligibility to estimate hearing difficulties and to evaluate hearing aids.