Toward Sound Localization Testing in Virtual Reality to Aid in the Screening of Auditory Processing Disorders.

Sound localization testing is key for comprehensive hearing evaluations, particularly in cases of suspected auditory processing disorders. However, sound localization is not commonly assessed in clinical practice, likely due to the complexity and size of conventional measurement systems, which require semicircular loudspeaker arrays in large and acoustically treated rooms. To address this issue, we investigated the feasibility of testing sound localization in virtual reality (VR). Previous research has shown that virtualization can lead to an increase in localization blur. To measure these effects, we conducted a study with a group of normal-hearing adults, comparing sound localization performance in different augmented reality and VR scenarios. We started with a conventional loudspeaker-based measurement setup and gradually moved to a virtual audiovisual environment, testing sound localization in each scenario using a within-participant design. The loudspeaker-based experiment yielded results comparable to those reported in the literature, and the results of the virtual localization test provided new insights into localization performance in state-of-the-art VR environments. By comparing localization performance between the loudspeaker-based and virtual conditions, we were able to estimate the increase in localization blur induced by virtualization relative to a conventional test setup. Notably, our study provides the first proxy normative cutoff values for sound localization testing in VR. As an outlook, we discuss the potential of a VR-based sound localization test as a suitable, accessible, and portable alternative to conventional setups and how it could serve as a time- and resource-saving prescreening tool to avoid unnecessarily extensive and complex laboratory testing.

Bayesian analysis of Ecological Momentary Assessment (EMA) data collected in adults before and after hearing rehabilitation.

This paper presents a new Bayesian method for analyzing Ecological Momentary Assessment (EMA) data and applies this method in a re-analysis of data from a previous EMA study. The analysis method has been implemented as a freely available Python package EmaCalc, RRID:SCR 022943. The analysis model can use EMA input data including nominal categories in one or more situation dimensions, and ordinal ratings of several perceptual attributes. The analysis uses a variant of ordinal regression to estimate the statistical relation between these variables. The Bayesian method has no requirements related to the number of participants or the number of assessments by each participant. Instead, the method automatically includes measures of the statistical credibility of all analysis results, for the given amount of data. For the previously collected EMA data, the analysis results demonstrate how the new tool can handle heavily skewed, scarce, and clustered data that were collected on ordinal scales, and present results on interval scales. The new method revealed results for the population mean that were similar to those obtained in the previous analysis by an advanced regression model. The Bayesian approach automatically estimated the inter-individual variability in the population, based on the study sample, and could show some statistically credible intervention results also for an unseen random individual in the population. Such results may be interesting, for example, if the EMA methodology is used by a hearing-aid manufacturer in a study to predict the success of a new signal-processing method among future potential customers.

Generalized expectile regression with flexible response function.

Expectile regression, in contrast to classical linear regression, allows for heteroscedasticity and omits a parametric specification of the underlying distribution. This model class can be seen as a quantile-like generalization of least squares regression. Similarly as in quantile regression, the whole distribution can be modeled with expectiles, while still offering the same flexibility in the use of semiparametric predictors as modern mean regression. However, even with no parametric assumption for the distribution of the response in expectile regression, the model is still constructed with a linear relationship between the fitted value and the predictor. If the true underlying relationship is nonlinear then severe biases can be observed in the parameter estimates as well as in quantities derived from them such as model predictions. We observed this problem during the analysis of the distribution of a self-reported hearing score with limited range. Classical expectile regression should in theory adhere to these constraints, however, we observed predictions that exceeded the maximum score. We propose to include a response function between the fitted value and the predictor similarly as in generalized linear models. However, including a fixed response function would imply an assumption on the shape of the underlying distribution function. Such assumptions would be counterintuitive in expectile regression. Therefore, we propose to estimate the response function jointly with the covariate effects. We design the response function as a monotonically increasing P-spline, which may also contain constraints on the target set. This results in valid estimates for a self-reported listening effort score through nonlinear estimates of the response function. We observed strong associations with the speech reception threshold.

Individual Hearing Aid Benefit in Real Life Evaluated Using Ecological Momentary Assessment.

Ecological momentary assessment (EMA) was used in 24 adults with mild-to-moderate hearing loss who were seeking first hearing-aid (HA) fitting or HA renewal. At two stages in the aural rehabilitation process, just before HA fitting and after an average 3-month HA adjustment period, the participants used a smartphone-based EMA system for 3 to 4 days. A questionnaire app allowed for the description of the environmental context as well as assessments of various hearing-related dimensions and of well-being. In total, 2,042 surveys were collected. The main objectives of the analysis were threefold: First, describing the "auditory reality" of future and experienced HA users; second, examining the effects of HA fitting for individual participants, as well as for the subgroup of first-time HA-users; and third, reviewing whether the EMA data collected in the unaided condition predicted who ultimately decided for or against permanent HA use. The participants reported hearing-related disabilities across the full range of daily listening tasks, but communication events took the largest share. The effect of the HA intervention was small in experienced HA users. Generally, much larger changes and larger interindividual differences were observed in first-time compared with experienced HA users in all hearing-related dimensions. Changes were not correlated with hearing loss or with the duration of the HA adjustment period. EMA data collected in the unaided condition did not predict the cancelation of HA fitting. The study showed that EMA is feasible in a general population of HA candidates for establishing individual and multidimensional profiles of real-life hearing experiences.

Sensitivity and specificity of a method for diagnosis of military noise-induced hearing loss.

Moore [(2020). J. Acoust. Soc. Am. 148, 884-894] proposed a method for the diagnosis of hearing loss produced by noise exposure during military service (denoted M-NIHL) based on the audiogram. This letter characterizes the sensitivity and specificity of the method, based on 116 ears of men claiming compensation for M-NIHL and 244 ears of an age-matched non-noise-exposed control group of men screened to match the noise-exposed group in age, absence of conductive hearing loss, no history of ear diseases, and asymmetry across ears ≤10 dB. The sensitivity was 0.97 and the specificity was 0.67, giving a discriminability index d' of 2.3.

Ecological Momentary Assessment in Hearing Research: Current State, Challenges, and Future Directions.

Common methods to assess hearing deficits and the benefit of hearing devices include retrospective questionnaires and speech tests under controlled conditions. As typically applied, both approaches suffer from serious limitations regarding their ecological validity. An alternative approach rapidly gaining widespread use is ecological momentary assessment (EMA), which employs repeated assessments of individual everyday situations. Smartphones facilitate the implementation of questionnaires and rating schemes to be administered in the real life of study participants or customers, during or shortly after an experience. In addition, objective acoustical parameters extracted from head- or body-worn microphones and/or settings from the hearing aid's signal processing unit can be stored alongside the questionnaire data. The advantages of using EMA include participant-specific, context-sensitive information on activities, experienced challenges, and preferences. However, to preserve the privacy of all communication partners and bystanders, the law in many countries does not allow audio recordings, limiting the information about environmental acoustics to statistical data such as, for example, levels and averaged spectra. Other challenges for EMA are, for example, the unsupervised handling of the equipment, the trade-off between the accuracy of description and the number of similar listening situations when performing comparisons (e.g., with and without hearing aids), the trade-off between the duration of recording intervals and the amount of data collected and analyzed, the random or target-oriented reminder for subjective responses, as well as the willingness and ability of the participants to respond while doing specific tasks. This contribution reviews EMA in hearing research, its purpose, current applications, and possible future directions.

Gender-specific hearing loss in German adults aged 18 to 84 years compared to US-American and current European studies.

INTRODUCTION: From an epidemiological point of view, the increase of pure-tone hearing thresholds as one aspect of biological ageing is moderated by societal factors. Since health policies refer to empirical findings, it is reasonable to replicate population-based hearing surveys and to compare estimates for different birth cohorts from the same regions or, conversely, for the same birth cohorts from different regions. METHODS: We pooled data from two independent cross-sectional German studies conducted between 2008 and 2012 and including 3105 adults. The increase of thresholds, the prevalence and risk of hearing impairment (HI) by age and gender were compared to results reported for European and US-American studies that were carried out at about the same time. Since these studies differed with regard to the age limits, the statistical approaches and, importantly, their definitions of HI, data adjustments were performed to enable the comparison. RESULTS: Overall, 15.5% of the participants in the German studies showed a pure-tone average at 0.5, 1, 2, and 4 kHz in the better ear (PTA) greater than 25 dB HL and 8.6% had a PTA of at least 35 dB HL. Based on one-to-one comparisons, the German estimates demonstrated a good agreement to a large Dutch study and with some reservations to a Swedish study, but considerable differences to US-American results. Comprehensive comparisons of the within-study gender differences showed that age-related HI was less and the gender gap was markedly smaller in Europe compared to the US due to the lower HI in males found in the European studies. CONCLUSION: Discrepancies in measurement procedures, conditions, and equipment that complicate the comparison of absolute HI estimates across studies play no or only a marginal role when comparing relative estimates. Hence, the gender gap differences reviewed in this analysis possibly stem from societal conditions that distinguish societies commonly labeled modern industrialized western countries.

Adjusting Expectations: Hearing Abilities in a Population-Based Sample Using an SSQ Short Form.

The German short form of the Speech, Spatial, and Qualities of Hearing Scale (SSQ) was administered in a cross-sectional study based on stratified random samples complemented by audiometric tests and a general interview. Data from 1,711 unaided adults aged 18 to 97 years were analyzed in order to determine a distribution of hearing abilities considered as normal and the main factors that impact self-assessments. An innovative mathematical approach was used to overcome the constraints of statistics based on the mean. Quantile regression analysis yielded a benchmark distribution of SSQ scores that might support audiologists in setting realistic SSQ score targets and estimated how the effect of auditory and nonauditory factors changes across the distribution of SSQ scores. Regression models showed significant effects for nonauditory factors on SSQ ratings when controlled for pure-tone hearing and interaural asymmetry. Self-reporting of hearing difficulties, when asked in general terms, was substantially related to SSQ ratings. This effect was observed in both high and low scoring participants and led to a considerable score decrease in all SSQ subscales. Gender, educational level, and self-reporting of health issues also were significantly related to SSQ ratings, but the corresponding effects were regularly unbalanced across the score distribution and particularly large at lower quantiles. The estimated effects of age, however, were mostly small in size, inconsistent regarding the direction, and failed significance for all SSQ items. Overall, the results suggest that nonauditory factors and cumulative effects must be considered when evaluating rehabilitative interventions against an ideal outcome.

[Hearing test results of 18- to 20-year old men preceding military conscription from 2008-2010]. / Hörtestergebnisse bei 18- bis 20-jährigen Männern aus Kreiswehrersatzämtern von 2008­2010.

OBJECTIVE: High-frequency hearing loss is known to increase with age, whereas the amount and rate of increase of hearing loss in younger people is still unclear. A large proportion of young age groups is expected to preserve normal hearing. Therefore, the requirements for screening methods are particularly high and the motivation to participate is low. The obligatory examinations preceding military conscription include a pure-tone audiogram and thus allow the analysis of the hearing status of young male adults. MATERIAL AND METHODS: The prevalence of hearing impairment was determined using air-conduction thresholds of 18- to 20-year old men, from 54 German registration offices (KWEA), measured in 2008 to 2010. The criterion was based on candidates exceeding a threshold of 20 dB HL for one of the frequencies 3, 4, or 6 kHz in at least one ear. This very strict criterion was compared to other definitions of hearing impairment. RESULTS: The prevalence of hearing impairment was, on average, 15.3 % and thus in the same range as in other studies. However, the results of single KWEA differed by up to a factor of 10. CONCLUSIONS: Due to high fluctuations in measurement quality in the KWEA, regional differences in hearing thresholds of young men are not resolvable and it remains unclear whether the hearing loss has increased in comparison to earlier studies. The high variability of measurements near thresholds requires permanent quality inspections. However, hearing thresholds derived from screening cannot be evaluated applying the same criteria as for hearing tests in audiological centers or studies.

[Hearing Loss and Speech Recognition in the Elderly]. / Hörverlust und Sprachverstehen im Alter.

Elderly people often complain about poor speech understanding in noisy environments. In clinical practice, speech tests under noise conditions are used to examine hearing ability. The HÖRSTAT study, conducted on a population-based random sample consisting of 1903 adults, used the Goettingen Sentence Test (GÖSA) under noise conditions along with pure-tone audiometry. Hearing impairment was defined as pure-tone average at 0.5, 1, 2 and 4 kHz (PTA-4) greater than 25 dB HL in the better ear (WHO criterion). As expected, pure-tone thresholds and speech recognition thresholds (SRT) in GÖSA worsened steadily with age. For a comparison of PTA-4, SRTGÖSA and self-reported hearing, analysis was limited to 553 adults aged 60-85 years with PTA-4 below 50 dB HL and SRTs measured with a constant 65 dB SPL noise level. The percentage of hearing-impaired increased from 13 % in the 60-65 year-old people to 60 % in those aged 80-85 years. Overall, 68 % of the 60-85 years adults showed normal hearing in terms of unimpaired hearing according to the WHO criterion. The SRTGÖSA of 66 % of the elderly adults with normal hearing, however, did not lie within the reference range established with young normal hearing subjects in the HÖRSTAT study (4.8 ± 1.8 dB SNR, mean±2 * standard deviation). Among the 553 elderly, only 24 % reached this reference range. PTA-4 and SRTGÖSA results showed moderate to good correlations (Pearson r = 0.562, within 5-years bands: 0.372-0.514). From PTA-4 ≥ 30 dB HL and SRTGÖSA ≥- 2 dB SNR, respectively, more than half of the subjects reported hearing difficulties. Despite the continuous decline of PTA-4 and SRTGÖSA with age, the proportion of self-reported hearing difficulties as well as the self-rated hearing ability score stagnated. From the age of 70 years onwards, the elderly in the HÖRSTAT sample tend to overestimate their hearing abilities and to underestimate their difficulties.

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

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.

Hearing threshold distribution and effect of screening in a population-based German sample.

OBJECTIVE: To establish the status of hearing in adults in Germany and the effects of screening for noise, tinnitus, ear diseases, and general health on the distribution of hearing threshold levels (HTL) DESIGN: A cross-sectional epidemiological study conducted between 2010 and 2012 in two middle-sized cities. STUDY SAMPLE: A total of 1903 adults aged 18 to 97 years from a randomized sample drawn from the local registration offices and stratified for age and gender. RESULTS: Dispersion and distribution of HTL data observed in the population-based sample are well in line with international results. However, median HTL tend to be better than in most recent international studies. Screening for "otological normality" improves the median HTL overall by 3 dB in males and 1 dB in females. This effect is strongly age-dependent in males and far less pronounced in females. While by and large HTL medians of females in the screened sample meet the values expected by ISO 7029:2000, HTL medians of males in middle and higher age cohorts are better than expected, especially in the frequencies above 2 kHz. CONCLUSIONS: This study supports international findings that in males, the age-related decrease in hearing sensitivity at high frequencies is smaller than described by ISO 7029:2000.