Trends in Hearing最新文献

Hearing aid fitting formulas intended for the pediatric population can differ by 6 to 25 dB in prescribed output across frequency leading to large variations in aided audibility. Children perceive these differences and have expressed preferences that favor more audibility for quiet speech and less audibility for noisy speech. In this study, the effect of variations in audibility consistent with hearing aid fittings for children was examined. Sixteen children and adolescents (9-17 years) with mild-to-moderate hearing loss participated. Hearing aids programed to National Acoustic Laboratories or Desired Sensation Level v5.0a targets were fitted to each participant. Also, separate programs with and without a low-level adaptive gain feature were provided with each prescription. Speech reception threshold (SRT) was measured as well as performance for four suprathreshold auditory tasks that increased in cognitive demand. These tasks were word recognition, nonword detection, multiword recall, and rapid word learning. A significant effect of fitting formula, but not low-level or adaptive gain, was observed for SRT. Significant effects of presentation level, fitting formula, and low-level gain were observed for word recognition. The effect of presentation level was significant for nonword detection, multiword recall, and rapid word learning but no other main effects or interactions were significant. Finally, word recognition and nonword detection increased significantly with audibility while multiword recall and word learning did not. The results suggest that audibility assists with the initial perception of auditory input but plays a smaller role in memory formation and learning.

Dynamic focusing cochlear implant strategies aim to emulate normal cochlear excitation patterns by varying the degree of current focusing as a function of input level. Results on the speech perception benefits of these strategies have been mixed. In previous studies, channel interaction coefficients (K), which mediate the relationship between current level and degree of focusing, were fixed across channels and participants. Fixing K without accounting for channel interaction and the current required to accurately stimulate target neurons may elicit suboptimal loudness growth and speech perception. This study tested whether individualizing K improved speech perception relative to fixed-K and monopolar strategies. Fourteen ears of implanted adults were programmed with 14-channel strategies matched on pulse duration, pulse rate, filtering, and loudness. Sentence recognition and vowel identification was measured at 60 dB SPL equivalent in quiet and four-talker babble. On the group level, speech recognition in quiet and noise was similar between strategies. On the individual level, there were participants who benefitted with dynamic focusing strategies for speech perception in noise. Patterns of benefit were generally unclear, beyond associations between focused thresholds, duration of hearing loss, and individual-K benefit. Participants rated dynamic focusing like monopolar in clarity and ease of listening. Almost all participants expressed their willingness to use the strategies in a take-home trial. These results suggest that while individualizing K does not benefit all, there are individuals who benefit, for which the electrode-neuron interface may play a role. Future studies will evaluate acclimatization of dynamic focusing strategies using take-home trials.

This study was aimed at assessing listening effort (LE) in quiet and in noisy daily life situations, in 481 adults with hearing aids (HAs) and 62 adults with normal hearing, using an Extended version of the Effort Assessment Scale (EEAS). Participants were invited to self-assess their LE in daily life, on a visual analog scale graded from 0 (no effort) to 10. The EEAS's internal structure identified two separate constructs pertaining to LE in quiet and LE in noise, each with good consistency (Cronbach's α > 0.83). A three-factor model explained 12% of the variance of the EEAS scores, with HA experience the most important one, and better ear hearing threshold (averaged across 0.5-4 kHz) and ear asymmetry as the other two factors. The EEAS subscales differed in behavior, with the LE in noise being the most dependent on HA experience, whereas LE in quiet depended more on better ear hearing threshold. In a subgroup of people with 6 months to less than 24 months HA experience, a significant decrease in LE in noise was observed with increasing HA experience (0.26 points decrease per year of HA experience), whereas in a group of people with at least 24 months of HA experience, a small increase in LE in noise was observed. This effect was not mediated by age, nor hearing threshold. The extended Effort Assessment Scale is therefore offering an assessment of both LE in quiet and LE in noise, with different dependence on HA experience and hearing thresholds.

Hearing threshold levels (HTLs) at 500-8,000 Hz from the National Health and Nutrition Examination Survey (NHANES) 2011-2012, 2015-2016, and 2017-2020 were analyzed for males and females ranging in age from 20 to 80-plus years (N = 8,795). HTLs for the 10th, 25th, 50th, 75th, and 90th percentiles are provided for males and females. Equations were generated to describe median HTLs as a function of age at each frequency. The medians generated for this unscreened dataset of U.S. adults were compared to those in Table B.3 of ISO 1999 (2013), which came from analyses of the NHANES 1999-2006 datasets. The ISO 1999 values were found to be slightly higher (worse) at several frequencies. The ISO 1999 (2013) median HTLs were 2 to 5 dB worse at 500 Hz for males and females and 2 to 8 dB worse at 4,000 and 6,000 Hz for males than the updated NHANES estimates. As in prior analyses of NHANES data, HTLs worsened with age, were better for females than males, and were better for Non-Hispanic Blacks than for Non-Hispanic Whites. The latter difference was observed for both males and females, was confined to frequencies above 2,000 Hz, and widened with increasing age.

Electroencephalography could serve as an objective tool to evaluate hearing aid benefit in infants who are developmentally unable to participate in hearing tests. We investigated whether speech-evoked envelope following responses (EFRs), a type of electroencephalography-based measure, could predict improved audibility with the use of a hearing aid in children with mild-to-severe permanent, mainly sensorineural, hearing loss. In 18 children, EFRs were elicited by six male-spoken band-limited phonemic stimuli--the first formants of /u/ and /i/, the second and higher formants of /u/ and /i/, and the fricatives /s/ and /∫/--presented together as /su∫i/. EFRs were recorded between the vertex and nape, when /su∫i/ was presented at 55, 65, and 75 dB SPL using insert earphones in unaided conditions and individually fit hearing aids in aided conditions. EFR amplitude and detectability improved with the use of a hearing aid, and the degree of improvement in EFR amplitude was dependent on the extent of change in behavioral thresholds between unaided and aided conditions. EFR detectability was primarily influenced by audibility; higher sensation level stimuli had an increased probability of detection. Overall EFR sensitivity in predicting audibility was significantly higher in aided (82.1%) than unaided conditions (66.5%) and did not vary as a function of stimulus or frequency. EFR specificity in ascertaining inaudibility was 90.8%. Aided improvement in EFR detectability was a significant predictor of hearing aid-facilitated change in speech discrimination accuracy. Results suggest that speech-evoked EFRs could be a useful objective tool in predicting hearing aid benefit in children with hearing loss.

Subjects utilizing a cochlear implant (CI) in one ear and a hearing aid (HA) on the contralateral ear suffer from mismatches in stimulation timing due to different processing latencies of both devices. This device delay mismatch leads to a temporal mismatch in auditory nerve stimulation. Compensating for this auditory nerve stimulation mismatch by compensating for the device delay mismatch can significantly improve sound source localization accuracy. One CI manufacturer has already implemented the possibility of mismatch compensation in its current fitting software. This study investigated if this fitting parameter can be readily used in clinical settings and determined the effects of familiarization to a compensated device delay mismatch over a period of 3-4 weeks. Sound localization accuracy and speech understanding in noise were measured in eleven bimodal CI/HA users, with and without a compensation of the device delay mismatch. The results showed that sound localization bias improved to 0°, implying that the localization bias towards the CI was eliminated when the device delay mismatch was compensated. The RMS error was improved by 18% with this improvement not reaching statistical significance. The effects were acute and did not further improve after 3 weeks of familiarization. For the speech tests, spatial release from masking did not improve with a compensated mismatch. The results show that this fitting parameter can be readily used by clinicians to improve sound localization ability in bimodal users. Further, our findings suggest that subjects with poor sound localization ability benefit the most from the device delay mismatch compensation.

The diagnosis of noise-induced hearing loss (NIHL) is based on three requirements: a history of exposure to noise with the potential to cause hearing loss; the absence of known causes of hearing loss other than noise exposure; and the presence of certain features in the audiogram. All current methods for diagnosing NIHL have involved examination of the typical features of the audiograms of noise-exposed individuals and the formulation of quantitative rules for the identification of those features. This article describes an alternative approach based on the use of multilayer perceptrons (MLPs). The approach was applied to databases containing the ages and audiograms of individuals claiming compensation for NIHL sustained during military service (M-NIHL), who were assumed mostly to have M-NIHL, and control databases with no known exposure to intense sounds. The MLPs were trained so as to classify individuals as belonging to the exposed or control group based on their audiograms and ages, thereby automatically identifying the features of the audiogram that provide optimal classification. Two databases (noise exposed and nonexposed) were used for training and validation of the MLPs and two independent databases were used for evaluation and further analyses. The best-performing MLP was one trained to identify whether or not an individual had M-NIHL based on age and the audiogram for both ears. This achieved a sensitivity of 0.986 and a specificity of 0.902, giving an overall accuracy markedly higher than for previous methods.

The reduction in spectral resolution by cochlear implants oftentimes requires complementary visual speech cues to facilitate understanding. Despite substantial clinical characterization of auditory-only speech measures, relatively little is known about the audiovisual (AV) integrative abilities that most cochlear implant (CI) users rely on for daily speech comprehension. In this study, we tested AV integration in 63 CI users and 69 normal-hearing (NH) controls using the McGurk and sound-induced flash illusions. To our knowledge, this study is the largest to-date measuring the McGurk effect in this population and the first that tests the sound-induced flash illusion (SIFI). When presented with conflicting AV speech stimuli (i.e., the phoneme "ba" dubbed onto the viseme "ga"), we found that 55 CI users (87%) reported a fused percept of "da" or "tha" on at least one trial. After applying an error correction based on unisensory responses, we found that among those susceptible to the illusion, CI users experienced lower fusion than controls-a result that was concordant with results from the SIFI where the pairing of a single circle flashing on the screen with multiple beeps resulted in fewer illusory flashes for CI users. While illusion perception in these two tasks appears to be uncorrelated among CI users, we identified a negative correlation in the NH group. Because neither illusion appears to provide further explanation of variability in CI outcome measures, further research is needed to determine how these findings relate to CI users' speech understanding, particularly in ecological listening conditions that are naturally multisensory.

The aim of this study was to assess feasibility of using electrophysiological auditory steady-state response (ASSR) masking for detecting dead regions (DRs). Fifteen normally hearing adults were tested using behavioral and electrophysiological tasks. In the electrophysiological task, ASSRs were recorded to a 2 kHz exponentially amplitude-modulated tone (AM2) presented within a notched threshold equalizing noise (TEN) whose center frequency (CF_NOTCH) varied. We hypothesized that, in the absence of DRs, ASSR amplitudes would be largest for CF_NOTCH at/or near the signal frequency. In the presence of a DR at the signal frequency, the largest ASSR amplitude would occur at a frequency (f_max) far away from the signal frequency. The AM2 and the TEN were presented at 60 and 75 dB SPL, respectively. In the behavioral task, for the same maskers as above, the masker level at which an AM and a pure tone could just be distinguished, denoted AM2ML, was determined, for low (10 dB above absolute AM2 threshold) and high (60 dB SPL) signal levels. We also hypothesized that the value of f_max would be similar for both techniques. The ASSR f_max values obtained from grand average ASSR amplitudes, but not from individual amplitudes, were consistent with our hypotheses. The agreement between the behavioral f_max and ASSR f_max was poor. The within-session ASSR-amplitude repeatability was good for AM2 alone, but poor for AM2 in notched TEN. The ASSR-amplitude variability between and within participants seems to be a major roadblock to developing our approach into an effective DR detection method.