Hearing Aids Reduce Self-Perceived Difficulties in Noise for Listeners With Normal Audiograms.

OBJECTIVES: This study assessed hearing aid benefits for people with a normal audiogram but hearing-in-noise problems in everyday listening situations. DESIGN: Exploratory double-blinded case-control study whereby participants completed retrospective questionnaires, ecological momentary assessments, speech-in-noise testing, and mental effort testing with and without hearing aids. Twenty-seven adults reporting speech-in-noise problems but normal air conduction pure-tone audiometry took part in the study. They were randomly separated into an experimental group that trialed mild-gain hearing aids with advanced directional processing and a control group fitted with hearing aids with no gain or directionality. RESULTS: Self-reports showed mild-gain hearing aids reduce hearing-in-noise difficulties and provide a better hearing experience (i.e., improved understanding, participation, and mood). Despite the self-reported benefits, the laboratory tests did not reveal a benefit from the mild-gain hearing aids, with no group differences on speech-in-noise tests or mental effort measures. Further, participants found the elevated cost of hearing aids to be a barrier for their adoption. CONCLUSIONS: Hearing aids benefit the listening experience in some listening situations for people with normal audiogram who report hearing difficulties in noise. Decreasing the price of hearing aids may lead to greater accessibility to those seeking remediation for their communication needs.

The value of headphone accommodations in Apple Airpods Pro for managing speech-in-noise hearing difficulties of individuals with normal audiograms.

OBJECTIVE: To investigate the extent to which Headphone Accommodations in Apple AirPods Pro attend to the hearing needs of individuals with normal audiograms who experience hearing difficulties in noisy environments. DESIGN: Single-arm interventional study using acoustic measures, speech-in-noise laboratory testing, and real-world measures via questionnaires and ecological momentary assessment. STUDY SAMPLE: Seventeen normal-hearing individuals (9 female, 21-59 years) with self-reported hearing-in-noise difficulties. RESULTS: Acoustic measures showed that, relative to unaided, AirPods Pro provided a SNR advantage of +5.4 dB. Speech intelligibility performance in laboratory testing increased 11.8% with AirPods Pro, relative to unaided. On average, participants trialling AirPods Pro in real-world noisy venues reported that their overall hearing experience was a bit better than without them. Five participants (29%) reported that they would continue using AirPods Pro in the future. The most relevant barriers that would discourage their future use were limited hearing benefit, discomfort, and stigma. CONCLUSIONS: Occasional use of AirPods Pro may help some individuals with normal audiograms ameliorate their speech-in-noise hearing difficulties. The identified barriers may inspire the development of new technological solutions aimed at providing an optimal management strategy for the hearing difficulties of this segment of the population.

Changes in Orientation Behavior due to Extended High-Frequency (5 to 10 kHz) Spatial Cues.

OBJECTIVES: Current hearing aids have a limited bandwidth, which limits the intelligibility and quality of their output, and inhibits their uptake. Recent advances in signal processing, as well as novel methods of transduction, allow for a greater useable frequency range. Previous studies have shown a benefit for this extended bandwidth in consonant recognition, talker-sex identification, and separating sound sources. To explore whether there would be any direct spatial benefits to extending bandwidth, we used a dynamic localization method in a realistic situation. DESIGN: Twenty-eight adult participants with minimal hearing loss reoriented themselves as quickly and accurately as comfortable to a new, off-axis near-field talker continuing a story in a background of far-field talkers of the same overall level in a simulated large room with common building materials. All stimuli were low-pass filtered at either 5 or 10 kHz on each trial. To further simulate current hearing aids, participants wore microphones above the pinnae and insert earphones adjusted to provide a linear, zero-gain response. RESULTS: Each individual trajectory was recorded with infra-red motion-tracking and analyzed for accuracy, duration, start time, peak velocity, peak velocity time, complexity, reversals, and misorientations. Results across listeners showed a significant increase in peak velocity and significant decrease in start and peak velocity time with greater (10 kHz) bandwidth. CONCLUSIONS: These earlier, swifter orientations demonstrate spatial benefits beyond static localization accuracy in plausible conditions; extended bandwidth without pinna cues provided more salient cues in a realistic mixture of talkers.

Achieved Gain and Subjective Outcomes for a Wide-Bandwidth Contact Hearing Aid Fitted Using CAM2.

OBJECTIVES: The objective of this study was to test the ability to achieve, maintain, and subjectively benefit from extended high-frequency amplification in a real-world use scenario, with a device that restores audibility for frequencies up to 10 kHz. DESIGN: A total of 78 participants (149 ears) with mild to moderately-severe sensorineural hearing loss completed one of two studies conducted across eight clinical sites. Participants were fitted with a light-driven contact hearing aid (the Earlens system) that directly drives the tympanic membrane, allowing extended high-frequency output and amplification with minimal acoustic feedback. Cambridge Method for Loudness Equalization 2 - High Frequency (CAM2)-prescribed gains for experienced users were used for initial fitting, and adjustments were made when required according to participant preferences for loudness and comfort or when measures of functional gain (FG) indicated that more or less gain was needed. Participants wore the devices for an extended period. Prescribed versus adjusted output and gain, frequency-specific FG, and self-perceived benefit assessed with the Abbreviated Profile of Hearing Aid Benefit, and a custom questionnaire were documented. Self-perceived benefit results were compared with those for unaided listening and to ratings with participants' own acoustic hearing aids. RESULTS: The prescribed low-level insertion gain from 6 to 10 kHz averaged 53 dB across all ears, with a range from 26 to 86 dB. After adjustment, the gain from 6 to 10 kHz decreased to an average of 45 dB with a range from 16 to 86 dB. Measured FG averaged 39 dB from 6 to 10 kHz with a range from 11 to 62 dB. Abbreviated Profile of Hearing Aid Benefit results revealed a significant improvement in communication relative to unaided listening, averaging 28 to 32 percentage points for the background noise, reverberation, and ease of communication subscales. Relative to participants' own hearing aids, the subscales ease of communication and aversiveness showed small but significant improvements for Earlens ranging from 6 to 7 percentage points. For the custom satisfaction questionnaire, most participants rated the Earlens system as better than their own hearing aids in most situations. CONCLUSIONS: Participants used and reported subjective benefit from the Earlens system. Most participants preferred slightly less gain at 6 to 10 kHz than prescribed for experienced users by CAM2, preferring similar gains to those prescribed for inexperienced users, but gains over the extended high frequencies were high relative to those that are currently available with acoustic hearing aids.

A Model of Auditory-Cognitive Processing and Relevance to Clinical Applicability.

Hearing loss and cognitive function interact in both a bottom-up and top-down relationship. Listening effort is tied to these interactions, and models have been developed to explain their relationship. The Ease of Language Understanding model in particular has gained considerable attention in its explanation of the effect of signal distortion on speech understanding. Signal distortion can also affect auditory scene analysis ability, however, resulting in a distorted auditory scene that can affect cognitive function, listening effort, and the allocation of cognitive resources. These effects are explained through an addition to the Ease of Language Understanding model. This model can be generalized to apply to all sounds, not only speech, representing the increased effort required for auditory environmental awareness and other nonspeech auditory tasks. While the authors have measures of speech understanding and cognitive load to quantify these interactions, they are lacking measures of the effect of hearing aid technology on auditory scene analysis ability and how effort and attention varies with the quality of an auditory scene. Additionally, the clinical relevance of hearing aid technology on cognitive function and the application of cognitive measures in hearing aid fittings will be limited until effectiveness is demonstrated in real-world situations.

Hearing Impairment and Cognitive Energy: The Framework for Understanding Effortful Listening (FUEL).

The Fifth Eriksholm Workshop on "Hearing Impairment and Cognitive Energy" was convened to develop a consensus among interdisciplinary experts about what is known on the topic, gaps in knowledge, the use of terminology, priorities for future research, and implications for practice. The general term cognitive energy was chosen to facilitate the broadest possible discussion of the topic. It goes back to who described the effects of attention on perception; he used the term psychic energy for the notion that limited mental resources can be flexibly allocated among perceptual and mental activities. The workshop focused on three main areas: (1) theories, models, concepts, definitions, and frameworks; (2) methods and measures; and (3) knowledge translation. We defined effort as the deliberate allocation of mental resources to overcome obstacles in goal pursuit when carrying out a task, with listening effort applying more specifically when tasks involve listening. We adapted Kahneman's seminal (1973) Capacity Model of Attention to listening and proposed a heuristically useful Framework for Understanding Effortful Listening (FUEL). Our FUEL incorporates the well-known relationship between cognitive demand and the supply of cognitive capacity that is the foundation of cognitive theories of attention. Our FUEL also incorporates a motivation dimension based on complementary theories of motivational intensity, adaptive gain control, and optimal performance, fatigue, and pleasure. Using a three-dimensional illustration, we highlight how listening effort depends not only on hearing difficulties and task demands but also on the listener's motivation to expend mental effort in the challenging situations of everyday life.

Spatial release of cognitive load measured in a dual-task paradigm in normal-hearing and hearing-impaired listeners.

This study investigated whether spatial separation between talkers helps reduce cognitive processing load, and how hearing impairment interacts with the cognitive load of individuals listening in multi-talker environments. A dual-task paradigm was used in which performance on a secondary task (visual tracking) served as a measure of the cognitive load imposed by a speech recognition task. Visual tracking performance was measured under four conditions in which the target and the interferers were distinguished by (1) gender and spatial location, (2) gender only, (3) spatial location only, and (4) neither gender nor spatial location. Results showed that when gender cues were available, a 15° spatial separation between talkers reduced the cognitive load of listening even though it did not provide further improvement in speech recognition (Experiment I). Compared to normal-hearing listeners, large individual variability in spatial release of cognitive load was observed among hearing-impaired listeners. Cognitive load was lower when talkers were spatially separated by 60° than when talkers were of different genders, even though speech recognition was comparable in these two conditions (Experiment II). These results suggest that a measure of cognitive load might provide valuable insight into the benefit of spatial cues in multi-talker environments.

Acclimatization to hearing aids.

OBJECTIVE: Evidence for a clinically significant effect of acclimatization to hearing aids is mixed. The aim of this study was to test for auditory acclimatization effects in new unilateral and bilateral adult hearing aid users. Hypotheses were i) there would be improvements in aided speech recognition in new hearing aid users, compared with unaided listening and with a control group of experienced hearing aid users, and ii) improvements would correlate with severity of hearing loss, hearing aid use, and cognitive capacity. DESIGN: Speech recognition in noise was measured for a 65 and a 75 dB SPL target with the Four Alternative Auditory Feature test. Speech recognition in noise was measured within 1 week of fitting and retested at 12 weeks postfitting in new hearing aid users (16 unilateral and 16 bilateral fit). A control group of experienced hearing aid users (n = 17) was tested over a similar time scale. Cognitive capacity (reaction time and working memory) was measured, and self-reported change in performance was assessed using the Speech, Spatial and Qualities of Hearing Scale. Hearing aid use was assessed via data logging at the completion of the study. RESULTS: Mean improvements in speech recognition of up to 4% were observed across conditions and across groups consistent with a general practice effect. On average there was no evidence of auditory acclimatization in the new hearing aid user groups in terms of improvement in aided listening conditions above that observed in unaided recognition or in the control group. There was no correlation between change in aided speech recognition and severity of hearing loss, hearing aid use, or cognitive capacity. New users reported significant improvement over time in aided performance on a self-report questionnaire compared with the control group. CONCLUSIONS: On average, there was no improvement over time in new users' aided speech recognition relative to unaided recognition or to the control group. This does not support a robust acclimatization effect with nonlinear hearing aids. Test-retest variability may obscure small average acclimatization effects; variability was not accounted for by individual differences in severity of hearing loss, hearing aid use, or cognitive capacity. New users' subjective report of increased benefit over time may be reflective of other aspects of adjustment to hearing aid use not examined in this study.

Effects of interferer facing orientation on speech perception by normal-hearing and hearing-impaired listeners.

There exist perceptible differences between sound emanating from a talker who faces and a talker who does not face a listener: Sound from a non-facing talker is attenuated and acquires a spectral tilt. The present study assessed the role that these facing-orientation cues play for speech perception. Digit identification for a frontal target talker in the presence of two spatially separated interfering talkers was measured for 10 normal-hearing (NH) and 11 hearing-impaired (HI) listeners. Overall-level differences and spectral tilts were reproduced by means of digital filtering and playback via loudspeakers. Both NH and HI listeners performed significantly better when the interfering talkers were simulated not to be facing them. Spectral tilts and level differences across talkers reduced target-interferer confusions. They enabled the NH listeners to sequentially stream the digits. This was not the case for the HI listeners, who showed smaller benefits, irrespective of whether they were aided by their own hearing aids or not. While hearing-aid amplification increased audibility, it may not have aided target-interferer segregation or target selection. The present results suggest that facing orientation cannot be neglected in the exploration of speech perception in multitalker situations.

Auditory acclimatization and hearing aids: late auditory evoked potentials and speech recognition following unilateral and bilateral amplification.

The aim of this study was to investigate changes in central auditory processing following unilateral and bilateral hearing aid fitting using a combination of physiological and behavioral measures: late auditory event-related potentials (ERPs) and speech recognition in noise, respectively. The hypothesis was that for fitted ears, the ERP amplitude would increase over time following hearing aid fitting in parallel with improvement in aided speech recognition. The N1 and P2 ERPs were recorded to 500 and 3000 Hz tones presented at 65, 75, and 85 dB sound pressure level to either the left or right ear. New unilateral and new bilateral hearing aid users were tested at the time of first fitting and after 12 weeks hearing aid use. A control group of long-term hearing aid users was tested over the same time frame. No significant changes in the ERP were observed for any group. There was a statistically significant 2% improvement in aided speech recognition over time for all groups, although this was consistent with a general test-retest effect. This study does not support the existence of an acclimatization effect observable in late ERPs following 12 weeks' hearing aid use.

Unilateral and bilateral hearing aids, spatial release from masking and auditory acclimatization.

Spatial release from masking (SRM) was tested within the first week of fitting and after 12 weeks hearing aid use for unilateral and bilateral adult hearing aid users. A control group of experienced hearing aid users completed testing over a similar time frame. The main research aims were (1) to examine auditory acclimatization effects on SRM performance for unilateral and bilateral hearing aid users, (2) to examine whether hearing aid use, level of hearing loss, age or cognitive ability mediate acclimatization, and (3) to compare and contrast the outcome of unilateral versus bilateral aiding on SRM. Hearing aid users were tested with and without hearing aids, with SRM calculated as the 50% speech recognition threshold advantage when maskers and target are spatially separated at ±90° azimuth to the listener compared to a co-located condition. The conclusions were (1) on average there was no improvement over time in familiar aided listening conditions, (2) there was large test-retest variability which may overshadow small average acclimatization effects; greater improvement was associated with better cognitive ability and younger age, but not associated with hearing aid use, and (3) overall, bilateral aids facilitated better SRM performance than unilateral aids.

Multichannel compression hearing aids: effect of channel bandwidth on consonant and vowel identification by hearing-impaired listeners.

Aided consonant and vowel identification was measured in 13 listeners with high-frequency sloping hearing losses. To investigate the influence of compression-channel analysis bandwidth on identification performance independent of the number of channels, performance was compared for three 17-channel compression systems that differed only in terms of their channel bandwidths. One compressor had narrow channels, one had widely overlapping channels, and the third had level-dependent channels. Measurements were done in quiet, in speech-shaped noise, and in a three-talker background. The results showed no effect of channel bandwidth, neither on consonant nor on vowel identification scores. This suggests that channel bandwidth per se has little influence on speech intelligibility when individually prescribed, frequency-varying compressive gain is provided.

The effect of presentation level on normal-hearing and hearing-impaired listeners' acceptable speech and noise levels.

BACKGROUND: Acceptable noise level (ANL) is a measure of the maximum amount of background noise that a listener is willing to "put up with" while listening to running speech. This test is unique in that it can predict with a high degree of accuracy who will be a successful hearing-aid wearer. Individuals who tolerate high levels of background noise are generally successful hearing-aid wearers, whereas individuals who do not tolerate background noise well are generally unsuccessful hearing-aid wearers. PURPOSE: Various studies have been unsuccessful in trying to relate ANLs to listener characteristics or other test results. Presumably, understanding the perceptual mechanism by which listeners determine their ANLs could provide an understanding of the ANL's unique predictive abilities and our current inability to correlate these results with other listener attributes or test results. As a first step in investigating this problem, the relationships between ANLs and other threshold measures where listeners adjust the signal-to-noise ratio (SNR) according to some criterion in a way similar to the ANL measure were examined. RESEARCH DESIGN AND STUDY SAMPLE: Ten normal-hearing and 10 hearing-impaired individuals participated in a laboratory experiment that followed a within-subjects, repeated-measures design. DATA COLLECTION AND ANALYSIS: Participants were seated in a sound booth. Running speech and noise (eight-talker babble) were presented from a loudspeaker at 0°, 3 ft in front of the participant. Individuals adjusted either the level of the speech or the level of the background noise. Specifically, with the speech fixed at different levels (50, 63, 75, or 88 dBA), participants performed the ANL task, in which they adjusted the level of the background noise to the maximum level at which they were willing to listen while following the speech. With the noise fixed at different levels (50, 60, 70, or 80 dBA), participants adjusted the level of the speech to the minimum, preferred, or maximum levels at which they were willing to listen while following the speech. Additionally, for the minimum acceptable speech level task, each participant was tested at four participant-specific noise levels, based on his/her ANL results. To emphasize that the speech level was adjusted in these measurements, three new terms were coined: "minimum acceptable speech level" (MinASL), "preferred speech level" (PSL), and "maximum acceptable speech level" (MaxASL). Each condition was presented twice, and the results were averaged. Test order and presentation level were randomized. Hearing-impaired participants were tested in the aided condition only. RESULTS: For most participants, as the presentation level increased, SNRs increased for the ANL test but decreased for the MinASL, PSL, and MaxASL tests. For a few participants, ANLs were similar to MinASLs. For most test conditions, the normal-hearing results were not significantly different from those of the hearing-impaired participants. CONCLUSIONS: For most participants, stimulus level affected the SNRs at which they were willing to listen. However, a subset of listeners was willing to listen at a constant SNR for the ANL and MinASL tests. Furthermore, for these individuals, ANLs and MinASLs were roughly equal, suggesting that these individuals may have used the same perceptual criterion for both tests.

Wolbachia interferes with Zika virus replication by hijacking cholesterol metabolism in mosquito cells.

IMPORTANCE: Arthropod-borne viruses are emerging pathogens that are spread widely by mosquitos. Zika virus is an arbovirus that can infect humans and be transmitted from an infected mother to the fetus, potentially leading to microcephaly in infants. One promising strategy to prevent disease caused by arboviruses is to target the insect vector population. Recent field studies have shown that mosquito populations infected with Wolbachia bacteria suppress arbovirus replication and transmission. Here, we describe how intracellular bacteria redirect resources within their host cells and suppress Zika virus replication at the cellular level. Understanding the mechanism behind Wolbachia-induced interference of arbovirus replication could help advance strategies to control arbovirus pathogens in insect vectors and human populations.

Scoping Review for a Global Hearing Care Framework: Matching Theory with Practice.

The hearing healthcare industry is evolving rapidly. A framework addressing provision options in contemporary hearing care could assist clinician and client navigate their options to find the most appropriate solution for each individual. A PRISMA approach was used followed by mapping, validation, and thematic analysis to produce a framework to better describe and discuss service and product delivery options in contemporary hearing care. No frameworks were identified to advise matching needs with current provision options in audiological care. Charting, mapping, and thematic analysis of the validation criteria and hearing care literature produced three core domains: Service, Channel, and Technology/Device. The framework developed in this review allows for an understanding of where innovation is occurring in hearing healthcare and differentiates between changes to technology, channel, and service. New questions open up such as whether one model is more effective than another or which model of hearing help is best for which type of person. This framework allows for the disambiguation of hearing health services, hearing loss technology, and the channel in which services and technology are delivered. It has potential to be a versatile and valuable addition to the industry of hearing healthcare.

Restoration of loudness summation and differential loudness growth in hearing-impaired listeners.

When normal-hearing (NH) listeners compare the loudness of narrowband and wideband sounds presented at identical sound pressure levels, the wideband sound will most often be perceived as louder than the narrowband sound, a phenomenon referred to as loudness summation. Hearing-impaired (HI) listeners typically show less-than-normal loudness summation, due to reduced cochlear compressive gain and degraded frequency selectivity. In the present study, loudness summation at 1 and 3 kHz was estimated monaurally for five NH and eight HI listeners by matching the loudness of narrowband and wideband noise stimuli. The loudness summation was measured as a function both of noise bandwidth and level. The HI listeners were tested unaided and aided using three different compression systems to investigate the possibility of restoring loudness summation in these listeners. A compression system employing level-dependent compression channels yielded the most promising outcome. The present results inform the development of future loudness models and advanced compensation strategies for the hearing impaired.

Assessing the benefit of adaptive null-steering using real-world signals.

This study compared the noise reduction of adaptive null-steering and near-hypercardioid directional hearing-aid algorithms via performance on real-world signals. Using subject-individualized and generic (i.e. similar to current hearing aids), off-line frequency-domain implementations, we processed recordings made through two microphones of a BTE device worn by five subjects. Recording scenarios included homes, offices, cafés, streets, buses, and automobiles. We found practically all (> 95% of recording time) adaptive noise-reduction benefit for generic implementations is below 1.2 dB, and 96% and 92% is below 2 dB for 16-and 32-band individualized implementations, respectively. A 256-band, individualized implementation showed a majority of benefit between 1-4 dB. We found no extended (> 2 s) continuous periods of significant (> 2 dB) benefit for the generic adaptive implementations. The recordings-having many independent and simultaneously active sources, spatially extended sources, significant reverberation, or combinations thereof-indicate an environment comprising few instances of high direct-to-diffuse energy situations. Combined with results from previous field trials, the evidence suggests that such an environment is common and represents a significant limitation on adaptive benefit.

A comparison of CIC and BTE hearing aids for three-dimensional localization of speech.

Three-dimensional sound localization of speech in anechoic space was examined for eleven listeners with sensorineural hearing loss. The listeners were fitted bilaterally with CIC and BTE hearing aids having similar bandwidth capabilities. The goal was to determine whether differences in microphone placement for these two styles (CICs at the ear canal entrance; BTEs above the pinna) would influence the availability of pinna-related spectral cues and hence localization performance. While lateral and polar angle localization was unaffected by the hearing aid style, the rate of front-back reversals was lower with CICs. This pattern persisted after listeners accommodated to each set of aids for a six week period, although the overall rate of reversals declined. Performance on all measures in all conditions was considerably poorer than in a control group of listeners with normal hearing.

Emerging Technologies, Market Segments, and MarkeTrak 10 Insights in Hearing Health Technology.

Hearing health care is rapidly changing through innovation in technology, services, business models, and product categories. The introduction of hearables and over-the-counter (OTC) hearing aids in particular will change the market for hearing help and the role of the hearing care professionals (HCPs). This article focuses on how these products will be differentiated from HCP-fit hearing aids through their ability to address the unmet needs of different consumer segments within the population of people with hearing dysfunction. The unmet hearing needs of each segment are discussed, and the size of each segment estimated, demonstrating a large potential market for hearables and a smaller potential market for hearing aids than has been previously mentioned in the literature. The results from MarkeTrak 10's survey of consumers' attitudes toward an OTC model are reviewed, showing that approximately half of both hearing aid owners and nonowners are uncomfortable doing hearing- and hearing aid-related tasks on their own without the assistance of an HCP and would be unlikely to purchase OTC hearing aids if available today. MarkeTrak data are also shown that demonstrate that the majority of hearing aid and personal sound amplification product owners believe that the HCP helped or would have helped with their hearing devices. Finally, challenges to OTC hearing aids becoming successful are discussed.