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Extended high frequencies (EHF), above 8 kHz, represent a region of the human hearing spectrum that is generally ignored by clinicians and researchers alike. This article is a compilation of contributions that, together, make the case for an essential role of EHF in both normal hearing and auditory dysfunction. We start with the fundamentals of biological and acoustic determinism – humans have EHF hearing for a purpose, for example, the detection of prey, predators, and mates. EHF hearing may also provide a boost to speech perception in challenging conditions and its loss, conversely, might help explain difficulty with the same task. However, it could be that EHF are a marker for damage in the conventional frequency region that is more related to speech perception difficulties. Measurement of EHF hearing in concert with otoacoustic emissions could provide an early warning of age-related hearing loss. In early life, when EHF hearing sensitivity is optimal, we can use it for enhanced phonetic identification during language learning, but we are also susceptible to diseases that can prematurely damage it. EHF audiometry techniques and standardization are reviewed, providing evidence that they are reliable to measure and provide important information for early detection, monitoring and possible prevention of hearing loss in populations at-risk. To better understand the full contribution of EHF to human hearing, clinicians and researchers can contribute by including its measurement, along with measures of speech in noise and self-report of hearing difficulties and tinnitus in clinical evaluations and studies. • Extended high frequency audiometry is reliable and sensitive to early cochlear damage. • Aging effects are revealed by extended high frequency thresholds and otoacoustic emissions. • Speech perception, especially in noise, is related to extended high frequency hearing sensitivity. [ABSTRACT FROM AUTHOR]

Purpose: This exploratory study assessed the perceptual, cognitive, and academic learning effects of an adaptive, integrated, directionality, and noise reduction hearing aid program in pediatric users. Method: Fifteen pediatric hearing aid users (6--12 years old) received new bilateral, individually fitted Oticon Opn hearing aids programmed with OpenSound Navigator (OSN) processing. Word recognition in noise, sentence repetition in quiet, nonword repetition, vocabulary learning, selective attention, executive function, memory, and reading and mathematical abilities were measured within 1 week of the initial hearing aid fitting and 2 months post fit. Caregivers completed questionnaires assessing their child's listening and communication abilities prior to study enrollment and after 2 months of using the study hearing aids. Results: Caregiver reporting indicated significant improvements in speech and sound perception, spatial sound awareness, and the ability to participate in conversations. However, there was no positive change in performance in any of the measured skills. Mathematical scores significantly declined after 2 months. Conclusions: OSN provided a perceived improvement in functional benefit, compared to their previous hearing aids, as reported by caregivers. However, there was no positive change in listening skills, cognition, and academic success after 2 months of using OSN. Findings may have been impacted by reporter bias, limited sample size, and a relatively short trial period. This study took place during the summer when participants were out of school, which may have influenced the decline in mathematical scores. The results support further exploration with age- and audiogrammatched controls, larger sample sizes, and longer test-- retest intervals that correspond to the academic school year. [ABSTRACT FROM AUTHOR]

Young healthy adults can hear tones up to at least 20 kHz. However, clinical audiometry, by which hearing loss is diagnosed, is limited at high frequencies to 8 kHz. Evidence suggests there is salient information at extended high frequencies (EHFs; 8 to 20 kHz) that may influence speech intelligibility, but whether that information is used in challenging listening conditions remains unknown. Difficulty understanding speech in noisy environments is the most common concern people have about their hearing and usually the first sign of age-related hearing loss. Digits-in-noise (DIN), a widely used test of speech-in-noise perception, can be sensitized for detection of high-frequency hearing loss by low-pass filtering the broadband masking noise. Here, we used standard and EHF audiometry, self-report, and successively higher cutoff frequency filters (2 to 8 kHz) in a DIN test to investigate contributions of higher-frequency hearing to speech-in-noise perception. Three surprising results were found. First, 74 of 116 “normally hearing,” mostly younger adults had some hearing loss at frequencies above 8 kHz. Early EHF hearing loss may thus be an easily measured, preventive warning to protect hearing. Second, EHF hearing loss correlated with self-reported difficulty hearing in noise. Finally, even with the broadest filtered noise (≤8 kHz), DIN hearing thresholds were significantly better (P < 0.0001) than those using broadband noise. Sound energy above 8 kHz thus contributes to speech perception in noise. People with “normal hearing” frequently report difficulty hearing in challenging environments. Our results suggest that one contribution to this difficulty is EHF hearing loss. [ABSTRACT FROM AUTHOR]