Audiometric profiles and patterns of benefit: a data-driven analysis of subjective hearing difficulties and handicaps.

OBJECTIVE: Hearing rehabilitation attempts to compensate for auditory dysfunction, reduce hearing difficulties and minimise participation restrictions that can lead to social isolation. However, there is no systematic approach to assess the quality of the intervention at an individual level that might help to evaluate the need of further hearing rehabilitation in the hearing care clinic. DESIGN: A data-driven analysis on subjective data reflecting hearing disabilities and handicap was chosen to explore "benefit patterns" as a result of rehabilitation in different audiometric groups. The method was based on (1) dimensionality reduction; (2) stratification; (3) archetypal analysis; (4) clustering; (5) item importance estimation. STUDY SAMPLE: 572 hearing-aid users completed questionnaires of hearing difficulties (speech, spatial and qualities hearing scale; SSQ) and hearing handicap (HHQ). RESULTS: The data-driven approach revealed four benefit profiles that were different for each audiometric group. The groups with low degree of high-frequency hearing loss (HLHF) showed a priority for rehabilitating hearing handicaps, whereas the groups with HLHF > 50 dB HL showed a priority for improvements in speech understanding. CONCLUSIONS: The patterns of benefit and the stratification approach might guide the clinical intervention strategy and improve the efficacy and quality of service in the hearing care clinic.

The Audible Contrast Threshold (ACT) test: A clinical spectro-temporal modulation detection test.

Over the last decade, multiple studies have shown that hearing-impaired listeners' speech-in-noise reception ability, measured with audibility compensation, is closely associated with performance in spectro-temporal modulation (STM) detection tests. STM tests thus have the potential to provide highly relevant beyond-the-audiogram information in the clinic, but the available STM tests have not been optimized for clinical use in terms of test duration, required equipment, and procedural standardization. The present study introduces a quick-and-simple clinically viable STM test, named the Audible Contrast Threshold (ACT™) test. First, an experimenter-controlled STM measurement paradigm was developed, in which the patient is presented bilaterally with a continuous audibility-corrected noise via headphones and asked to press a pushbutton whenever they hear an STM target sound in the noise. The patient's threshold is established using a Hughson-Westlake tracking procedure with a three-out-of-five criterion and then refined by post-processing the collected data using a logistic function. Different stimulation paradigms were tested in 28 hearing-impaired participants and compared to data previously measured in the same participants with an established STM test paradigm. The best stimulation paradigm showed excellent test-retest reliability and good agreement with the established laboratory version. Second, the best stimulation paradigm with 1-second noise "waves" (windowed noise) was chosen, further optimized with respect to step size and logistic-function fitting, and tested in a population of 25 young normal-hearing participants using various types of transducers to obtain normative data. Based on these normative data, the "normalized Contrast Level" (in dB nCL) scale was defined, where 0 ± 4 dB nCL corresponds to normal performance and elevated dB nCL values indicate the degree of audible contrast loss. Overall, the results of the present study suggest that the ACT test may be considered a reliable, quick-and-simple (and thus clinically viable) test of STM sensitivity. The ACT can be measured directly after the audiogram using the same set up, adding only a few minutes to the process.

Amplitude Compression for Preventing Rollover at Above-Conversational Speech Levels.

Hearing aids provide nonlinear amplification to improve speech audibility and loudness perception. While more audibility typically increases speech intelligibility at low levels, the same is not true for above-conversational levels, where decreases in intelligibility ("rollover") can occur. In a previous study, we found rollover in speech intelligibility measurements made in quiet for 35 out of 74 test ears with a hearing loss. Furthermore, we found rollover occurrence in quiet to be associated with poorer speech intelligibility in noise as measured with linear amplification. Here, we retested 16 participants with rollover with three amplitude-compression settings. Two were designed to prevent rollover by applying slow- or fast-acting compression with a 5:1 compression ratio around the "sweet spot," that is, the area in an individual performance-intensity function with high intelligibility and listening comfort. The third, reference setting used gains and compression ratios prescribed by the "National Acoustic Laboratories Non-Linear 1" rule. Speech intelligibility was assessed in quiet and in noise. Pairwise preference judgments were also collected. For speech levels of 70 dB SPL and above, slow-acting sweet-spot compression gave better intelligibility in quiet and noise than the reference setting. Additionally, the participants clearly preferred slow-acting sweet-spot compression over the other settings. At lower levels, the three settings gave comparable speech intelligibility, and the participants preferred the reference setting over both sweet-spot settings. Overall, these results suggest that, for listeners with rollover, slow-acting sweet-spot compression is beneficial at 70 dB SPL and above, while at lower levels clinically established gain targets are more suited.

Auditory Profile-Based Hearing Aid Fitting: Self-Reported Benefit for First-Time Hearing Aid Users.

Background: Although hearing aids (HAs) can compensate for reduced audibility, functional outcomes and benefits vary widely across individuals. As part of the Danish 'Better hEAring Rehabilitation' (BEAR) project, four distinct auditory profiles differing in terms of audiometric thresholds and supra-threshold hearing abilities were recently identified. Additionally, profile-specific HA-fitting strategies were proposed. The aim of the current study was to evaluate the self-reported benefit of these profile-based HA fittings in a group of new HA users. Methods: A total of 205 hearing-impaired older adults were recruited from two Danish university hospitals. Participants were randomly allocated to one of two treatment groups: (1) NAL-NL2 gain prescription combined with default advanced feature settings ('reference fitting') or (2) auditory profile-based fitting with tailored gain prescription and advanced feature settings ('BEAR fitting'). Two months after treatment, the participants completed the benefit version of the short form of the Speech, Spatial, and Qualities of Hearing Scale (SSQ12-B) and the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaire. Results: Overall, participants reported a clear benefit from HA treatment. However, no significant differences in the SSQ12-B or IOI-HA scores between the reference and BEAR fittings were found. Conclusion: First-time users experience clear benefits from HA treatment. Auditory profile-based HA fitting warrants further investigation.

Comparison of hearing aid fitting effectiveness with audiograms from either user-operated or traditional audiometry in a clinical setting: a study protocol for a blinded non-inferiority randomised controlled trial.

INTRODUCTION: There is a worldwide need to enhance the capacity of audiometry testing. The objective of this study is to compare the User-operated Audiometry (UAud) system with traditional audiometry in a clinical setting, by investigating if hearing aid effectiveness based on UAud is non-inferior to hearing aid effectiveness based on traditional audiometry, and whether thresholds obtained with the user-operated version of the Audible Contrast Threshold (ACT) test correlates to traditional measures of speech intelligibility. METHODS AND ANALYSIS: The design will be a blinded non-inferiority randomised controlled trial. 250 adults referred for hearing aid treatment will be enrolled in the study. Study participants will be tested using both traditional audiometry as well as the UAud system and they will answer the questionnaire Speech, Spatial and Qualities of Hearing Scale (SSQ12) at baseline. Participants will be randomly divided to receive hearing aids fitted based on either UAud or traditional audiometry. Three months after participants have started using their hearing aids, they will undergo a hearing in noise test with hearing aids to measure their speech-in-noise performance and answer the following questionnaires: SSQ12, the Abbreviated Profile of Hearing Aid Benefit and the International Outcome Inventory for Hearing Aids. The primary outcome is a comparison of the change in SSQ12 scores from baseline to follow-up between the two groups. Participants will undergo the user-operated ACT test of spectro-temporal modulation sensitivity as part of the UAud system. The ACT results will be compared with measures of speech intelligibility from the traditional audiometry session and follow-up measurements. ETHICS AND DISSEMINATION: The project was evaluated by the Research Ethics Committee of Southern Denmark and judged not to need approval. The findings will be submitted to an international peer-reviewed journal and presented at national and international conferences. TRIAL REGISTRATION NUMBER: NCT05043207.

Corrigendum: Auditory tests for characterizing hearing deficits in listeners with various hearing abilities: The BEAR test battery.

[This corrects the article DOI: 10.3389/fnins.2021.724007.].

Towards Auditory Profile-Based Hearing-Aid Fittings: BEAR Rationale and Clinical Implementation.

(1) Background: To improve hearing-aid rehabilitation, the Danish 'Better hEAring Rehabilitation' (BEAR) project recently developed methods for individual hearing loss characterization and hearing-aid fitting. Four auditory profiles differing in terms of audiometric hearing loss and supra-threshold hearing abilities were identified. To enable auditory profile-based hearing-aid treatment, a fitting rationale leveraging differences in gain prescription and signal-to-noise (SNR) improvement was developed. This report describes the translation of this rationale to clinical devices supplied by three industrial partners. (2) Methods: Regarding the SNR improvement, advanced feature settings were proposed and verified based on free-field measurements made with an acoustic mannikin fitted with the different hearing aids. Regarding the gain prescription, a clinically feasible fitting tool and procedure based on real-ear gain adjustments were developed. (3) Results: Analyses of the collected real-ear gain and SNR improvement data confirmed the feasibility of the clinical implementation. Differences between the auditory profile-based fitting strategy and a current 'best practice' procedure based on the NAL-NL2 fitting rule were verified and are discussed in terms of limitations and future perspectives. (4) Conclusion: Based on a joint effort from academic and industrial partners, the BEAR fitting rationale was transferred to commercially available hearing aids.

Towards Auditory Profile-Based Hearing-Aid Fitting: Fitting Rationale and Pilot Evaluation.

Background-The clinical characterization of hearing deficits for hearing-aid fitting purposes is typically based on the pure-tone audiogram only. In a previous study, a group of hearing-impaired listeners completed a comprehensive test battery that was designed to tap into different dimensions of hearing abilities. A data-driven analysis of the data yielded four clinically relevant patient sub-populations or "auditory profiles". The purpose of the current study was to propose and pilot-test profile-based hearing-aid settings in order to explore their potential for providing more targeted hearing-aid treatment. Methods-Four candidate hearing-aid settings were developed and evaluated by a subset of the participants tested previously. The evaluation consisted of multi-comparison preference ratings that were carried out in realistic sound scenarios. Results-Listeners belonging to the different auditory profiles showed different patterns of preference for the tested hearing-aid settings that were largely consistent with the expectations. Conclusions-The results of this pilot evaluation support further investigations into stratified, profile-based hearing-aid fitting with wearable hearing aids.

User-Operated Audiometry Project (UAud) - Introducing an Automated User-Operated System for Audiometric Testing Into Everyday Clinic Practice.

Hearing loss is the third leading cause of years lived with disability. It is estimated that 430 million people worldwide are affected, and the number of cases is expected to increase in the future. There is therefore increased pressure on hearing health systems around the world to improve efficiency and reduce costs to ensure increased access to quality hearing health care. Here, we describe the User-Operated Audiometry project, the goal of which is to introduce an automated system for user-operated audiometric testing into everyday clinic practice as a means to relieve part of this pressure. The alternative to the existing referral route is presented in which examination is executed via the user-operated system. This route is conceptualized as an interaction between the patient, the system, and the hearing care professional (HCP). Technological requirements of the system and challenges that are related to the interaction between patients, the user-operated system, and the HCPs within the specific medical setting are discussed. Lastly, a strategy for the development and implementation of user-operated audiometry is presented, which includes initial investigations, a validation study, and implementation in a real-life clinical situation.

Auditory Tests for Characterizing Hearing Deficits in Listeners With Various Hearing Abilities: The BEAR Test Battery.

The Better hEAring Rehabilitation (BEAR) project aims to provide a new clinical profiling tool-a test battery-for hearing loss characterization. Although the loss of sensitivity can be efficiently measured using pure-tone audiometry, the assessment of supra-threshold hearing deficits remains a challenge. In contrast to the classical "attenuation-distortion" model, the proposed BEAR approach is based on the hypothesis that the hearing abilities of a given listener can be characterized along two dimensions, reflecting independent types of perceptual deficits (distortions). A data-driven approach provided evidence for the existence of different auditory profiles with different degrees of distortions. Ten tests were included in a test battery, based on their clinical feasibility, time efficiency, and related evidence from the literature. The tests were divided into six categories: audibility, speech perception, binaural processing abilities, loudness perception, spectro-temporal modulation sensitivity, and spectro-temporal resolution. Seventy-five listeners with symmetric, mild-to-severe sensorineural hearing loss were selected from a clinical population. The analysis of the results showed interrelations among outcomes related to high-frequency processing and outcome measures related to low-frequency processing abilities. The results showed the ability of the tests to reveal differences among individuals and their potential use in clinical settings.

Robust Data-Driven Auditory Profiling Towards Precision Audiology.

The sources and consequences of a sensorineural hearing loss are diverse. While several approaches have aimed at disentangling the physiological and perceptual consequences of different etiologies, hearing deficit characterization and rehabilitation have been dominated by the results from pure-tone audiometry. Here, we present a novel approach based on data-driven profiling of perceptual auditory deficits that attempts to represent auditory phenomena that are usually hidden by, or entangled with, audibility loss. We hypothesize that the hearing deficits of a given listener, both at hearing threshold and at suprathreshold sound levels, result from two independent types of "auditory distortions." In this two-dimensional space, four distinct "auditory profiles" can be identified. To test this hypothesis, we gathered a data set consisting of a heterogeneous group of listeners that were evaluated using measures of speech intelligibility, loudness perception, binaural processing abilities, and spectrotemporal resolution. The subsequent analysis revealed that distortion type-I was associated with elevated hearing thresholds at high frequencies and reduced temporal masking release and was significantly correlated with elevated speech reception thresholds in noise. Distortion type-II was associated with low-frequency hearing loss and abnormally steep loudness functions. The auditory profiles represent four robust subpopulations of hearing-impaired listeners that exhibit different degrees of perceptual distortions. The four auditory profiles may provide a valuable basis for improved hearing rehabilitation, for example, through profile-based hearing-aid fitting.

Investigating the Effects of Four Auditory Profiles on Speech Recognition, Overall Quality, and Noise Annoyance With Simulated Hearing-Aid Processing Strategies.

Effective hearing aid (HA) rehabilitation requires personalization of the HA fitting parameters, but in current clinical practice only the gain prescription is typically individualized. To optimize the fitting process, advanced HA settings such as noise reduction and microphone directionality can also be tailored to individual hearing deficits. In two earlier studies, an auditory test battery and a data-driven approach that allow classifying hearing-impaired listeners into four auditory profiles were developed. Because these profiles were found to be characterized by markedly different hearing abilities, it was hypothesized that more tailored HA fittings would lead to better outcomes for such listeners. Here, we explored potential interactions between the four auditory profiles and HA outcome as assessed with three different measures (speech recognition, overall quality, and noise annoyance) and six HA processing strategies with various noise reduction, directionality, and compression settings. Using virtual acoustics, a realistic speech-in-noise environment was simulated. The stimuli were generated using a HA simulator and presented to 49 habitual HA users who had previously been profiled. The four auditory profiles differed clearly in terms of their mean aided speech reception thresholds, thereby implying different needs in terms of signal-to-noise ratio improvement. However, no clear interactions with the tested HA processing strategies were found. Overall, these findings suggest that the auditory profiles can capture some of the individual differences in HA processing needs and that further research is required to identify suitable HA solutions for them.

Data-Driven Approach for Auditory Profiling and Characterization of Individual Hearing Loss.

Pure-tone audiometry still represents the main measure to characterize individual hearing loss and the basis for hearing-aid fitting. However, the perceptual consequences of hearing loss are typically associated not only with a loss of sensitivity but also with a loss of clarity that is not captured by the audiogram. A detailed characterization of a hearing loss may be complex and needs to be simplified to efficiently explore the specific compensation needs of the individual listener. Here, it is hypothesized that any listener's hearing profile can be characterized along two dimensions of distortion: Type I and Type II. While Type I can be linked to factors affecting audibility, Type II reflects non-audibility-related distortions. To test this hypothesis, the individual performance data from two previous studies were reanalyzed using an unsupervised-learning technique to identify extreme patterns in the data, thus forming the basis for different auditory profiles. Next, a decision tree was determined to classify the listeners into one of the profiles. The analysis provides evidence for the existence of four profiles in the data. The most significant predictors for profile identification were related to binaural processing, auditory nonlinearity, and speech-in-noise perception. This approach could be valuable for analyzing other data sets to select the most relevant tests for auditory profiling and propose more efficient hearing-deficit compensation strategies.