Perceived Sound Quality Dimensions Influencing Frequency-Gain Shaping Preferences for Hearing Aid-Amplified Speech and Music

Variability of Preference-Based Adjustments on Hearing Aid Frequency-Gain Response

PURPOSE

Although users can customize the frequency-gain response of hearing aids, the variability in their individual adjustments remains a concern. This study investigated the within-subject variability in the gain adjustments made within a single self-adjustment procedure.

METHOD

Two experiments were conducted with 20 older adults with mild-to-severe hearing loss. Participants used a two-dimensional touchscreen to adjust hearing aid amplification across six frequency bands (0.25-8 kHz) while listening to continuous speech in background noise. In these two experiments, two user interface designs, differing in control-to-gain map, were tested. For each participant, the statistical properties of 30 repeated gain adjustments within a single self-adjustment procedure were analyzed.

RESULTS

When participants made multiple gain adjustments, their preferred gain settings showed the highest variability in the 4- and 8-kHz frequency bands and the lowest variability in the 1- and 2-kHz bands, suggesting that midfrequency bands are weighted more heavily in their preferences compared to high frequencies. Additionally, significant correlations were observed for the preferred gains between the 0.25- and 0.5-kHz bands, between the 0.5- and 1-kHz bands, and between the 4- and 8-kHz bands. Lastly, the standard error of the preferred gain reduced with an increasing number of trials, with a rate close to being slightly shallower than would be expected for invariant mean preference for most participants, suggesting convergent estimation of the underlying preference across trials.

CONCLUSION

Self-adjustments of frequency-gain profiles are informative about the underlying preference; however, the contributions from various frequency bands are neither equal nor independent.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.28405397.

Performance of hybrid gain formula versus traditional fitting formulas in hearing aid fitting in tinnitus patients with hearing loss

PURPOSE

Hearing aid fitting can be challenging when tinnitus accompanies hearing loss, as speech intelligibility and quality of life are affected by both hearing loss and tinnitus perception. However, studies focusing on the optimal hearing aid fitting for this group are scarce. Here, we aim to investigate the performance of alternative hearing aid fitting scenarios in improving hearing aid benefit and managing tinnitus.

METHODS

Sixty-six participants were included in the study and randomly divided into three groups based on the fitting formula: NAL-NL2, DSL pediatric and hybrid gain fitting procedure (covering NAL-NL2 for low frequencies and DSL pediatric formulas for high frequencies). Hearing aid benefit was evaluated using the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire and speech perception in noise (SPIN). To evaluate tinnitus perception, psychoacoustic characteristics of tinnitus were determined, and the Tinnitus Handicap Inventory (THI) was gathered.

RESULTS

The NAL-NL2 fitting procedure showed better results in hearing aid benefit and SPIN compared to the DSL pediatric procedure. In the DSL pediatric procedure, better results were obtained in tinnitus management compared to NAL-NL2. There was no difference between the hybrid fitting procedure and DSL pediatric in tinnitus management. The hybrid fitting procedure also did not differ from NAL-NL2 in SPIN and hearing aid benefit.

CONCLUSION

Here, we propose a hybrid gain fitting procedure that can be a better alternative to boost hearing aid performance and tinnitus management in clinical practice.

Examining Force Level Output of Skin-Drive Bone Conduction Hearing Devices in Adults With Simulated Conductive Hearing Loss

PURPOSE

Bone conduction hearing devices (BCDs) that deliver sound across the skin (i.e., transcutaneous) are suitable for some individuals who have conductive or mixed hearing losses. Prescriptive targets for percutaneous devices are available, for example, from the Desired Sensation Level-Bone Conduction Hearing Device (DSL-BCD) algorithm. These targets, however, may require modification for use with transcutaneous BCDs. The current study investigated three key variables that may inform target modification: (a) comparison of thresholds measured using an audiometric bone conduction (BC) transducer versus transcutaneous BCDs that offer in situ threshold measurement, (b) transcutaneous BCD default force level outputs versus recommended DSL percutaneous BC targets, and (c) the preferred listening levels (PLLs) of adults wearing transcutaneous BCDs in a laboratory setting.

METHOD

Bilateral conductive hearing loss was simulated in 20 normal-hearing adults via earplugs. Thresholds were measured using a B-71 BC transducer and two commercially available BCDs coupled to a soft headband. DSL percutaneous BC targets were generated, and PLLs were obtained for a 60-dB SPL speech stimulus. Force level outputs were measured using a skull simulator on the Audioscan Verifit2 at the hearing aids' default settings and at the participants' PLL for each device.

RESULTS

On average, audiometric BC thresholds were significantly better than those measured in situ with each BCD. PLLs were similar to prescribed targets for one device with the smoother response shape and agreed in the high frequencies for both devices.

CONCLUSIONS

In situ thresholds are significantly higher than audiometric BC thresholds, suggesting that device-based in situ measurement more accurately accounts for the signal transmission from transcutaneous BCDs. PLLs differed from the percutaneous targets and varied between devices, which may indicate that either target modifications or manipulations of device frequency response shaping are needed to approximate PLL with transcutaneous BCD devices.

Hearing aid evaluation for music: Accounting for acoustical variability of music stimuli

Music is an important signal class for hearing aids, and musical genre is often used as a descriptor for stimulus selection. However, little research has systematically investigated the acoustical properties of musical genres with respect to hearing aid amplification. Here, extracts from a combination of two comprehensive music databases were acoustically analyzed. Considerable overlap in acoustic descriptor space between genres emerged. By simulating hearing aid processing, it was shown that effects of amplification regarding dynamic range compression and spectral weighting differed across musical genres, underlining the critical role of systematic stimulus selection for research on music and hearing aids.

Pedagogical Approaches in Music and Audio Education for Deaf and Hard-of-Hearing Students

Learning about music, sound or audio can present significant challenges for individuals who are deaf and hard of hearing (DHH). Given the advancements in technology and the increasing emphasis on equality, diversity and inclusion (EDI) in education, this article proposes pedagogical approaches aimed at facilitating the learning process for DHH students in the areas of music and audio production. These approaches encompass sound visualisation, haptic feedback, automated transcription, tactics in non-linear editing and digital signal processing. Importantly, these approaches do not necessitate advanced technical skills or substantial additional resources, thus lowering barriers for DHH students to overcome challenges in music and audio production. Furthermore, these strategies would enable content creation and editing for individuals with DHH, who may have previously been excluded from participating in music and audio production. Recommendations are provided for the implementation of these approaches in diverse educational settings to promote the integration of EDI in music and audio education.

Validation of an integrated pressure level measured earmold wideband real-ear-to-coupler difference measurement

OBJECTIVE

To validate measurement of predicted earmold wideband real-ear-to-coupler difference (wRECD) using an integrated pressure level (IPL) calibrated transducer and the incorporation of an acoustically measured tubing length correction.

DESIGN

Unilateral earmold SPL wRECD using varied hearing aid tubing length and the proposed predicted earmold IPL wRECD measurement procedure were completed on all participants and compared.

STUDY SAMPLE

22 normal hearing adults with normal middle ear status were recruited.

RESULTS

There were no clinically significant differences between probe-microphone and predicted earmold IPL wRECD measurements between 500 and 2500 Hz. Above 5000 Hz, the predicted earmold IPL wRECD exceeded earmold SPL wRECDs due to lack of standing wave interference. Test-retest reliability of IPL wRECD measurement exceeded the reliability of earmold SPL wRECD measurement across all assessed frequencies, with the greatest improvements in the high frequencies. The acoustically measured tubing length correction largely accounted for acoustic effects of the participant's earmold.

CONCLUSIONS

IPL-based measurements provide a promising alternative to probe-microphone earmold wRECD procedures. Predicted earmold IPL wRECD is measured without probe-microphone placement, agrees well with earmold SPL wRECDs and is expected to extend the valid bandwidth of wRECD measurement.

Muddy, muddled, or muffled? Understanding the perception of audio quality in music by hearing aid users

Introduction

Previous work on audio quality evaluation has demonstrated a developing convergence of the key perceptual attributes underlying judgments of quality, such as timbral, spatial and technical attributes. However, across existing research there remains a limited understanding of the crucial perceptual attributes that inform audio quality evaluation for people with hearing loss, and those who use hearing aids. This is especially the case with music, given the unique problems it presents in contrast to human speech.

Method

This paper presents a sensory evaluation study utilising descriptive analysis methods, in which a panel of hearing aid users collaborated, through consensus, to identify the most important perceptual attributes of music audio quality and developed a series of rating scales for future listening tests. Participants (N = 12), with a hearing loss ranging from mild to severe, first completed an online elicitation task, providing single-word terms to describe the audio quality of original and processed music samples; this was completed twice by each participant, once with hearing aids, and once without. Participants were then guided in discussing these raw terms across three focus groups, in which they reduced the term space, identified important perceptual groupings of terms, and developed perceptual attributes from these groups (including rating scales and definitions for each).

Results

Findings show that there were seven key perceptual dimensions underlying music audio quality (clarity, harshness, distortion, spaciousness, treble strength, middle strength, and bass strength), alongside a music audio quality attribute and possible alternative frequency balance attributes.

Discussion

We outline how these perceptual attributes align with extant literature, how attribute rating instruments might be used in future work, and the importance of better understanding the music listening difficulties of people with varied profiles of hearing loss.

Feasibility of hearing aid gain self-adjustment using speech recognition

Personal hearing devices, such as hearing aids, may be fine-tuned by allowing the users to conduct self-adjustment. Two self-adjustment procedures were developed to collect the listener preferred gains in six octave-frequency bands from 0.25 kHz to 8 kHz. These procedures were designed to allow rapid exploration of a multi-dimensional parameter space using a simple, one-dimensional user control interface (i.e., a programmable knob). The two procedures differ in whether the user interface controls the gains in all frequency bands simultaneously (Procedure A) or only the gain in one frequency band (Procedure B) on a given trial. Monte-Carlo simulations suggested that for both procedures the gain preference identified by simulated listeners rapidly converged to the ground-truth preferred gain profile over the first 20 trials. Initial behavioral evaluations of the self-adjustment procedures, in terms of test-retest reliability, were conducted using 20 young, normal-hearing listeners. Each estimate of the preferred gain profile took less than 20 minutes. The deviation between two separate estimates of the preferred gain profile, conducted at least a week apart, was about 10 dB ~ 15 dB.

Open community platform for hearing aid algorithm research: open Master Hearing Aid (openMHA)

open Master Hearing Aid (openMHA) was developed and provided to the hearing aid research community as an open-source software platform with the aim to support sustainable and reproducible research towards improvement and new types of assistive hearing systems not limited by proprietary software. The software offers a flexible framework that allows the users to conduct hearing aid research using tools and a number of signal processing plugins provided with the software as well as the implementation of own methods. The openMHA software is independent of a specific hardware and supports Linux, macOS and Windows operating systems as well as 32-bit and 64-bit ARM-based architectures such as used in small portable integrated systems. www.openmha.org.