Reference Data Set of Extended High-Frequency Audiometry in Young, Middle, and Older Populations

PURPOSE: Elevated thresholds in the extended high-frequency hearing range have been associated with functional hearing deficits, such as poorer speech-in-noise performance. However, unlike the standard-frequency range, there is not normative data from the International Organization for Standardization (ISO) and no recommendations from the World Health Organization (WHO) regarding a normative cutoff value for normal hearing in the extended high frequencies, limiting clinical implications for extended high-frequency threshold measurement. In the present study, we report a proposed reference data set characterizing the extended high-frequency region in 717 participants aged 18-88 years evaluated on typical clinical equipment using a methodology from both the ISO and the WHO. We hypothesized that extended high-frequency thresholds would worsen with age, show reliable test-retest inspection, and show marked elevation even in those listeners who present normal-hearing thresholds in the standard-frequency range. Sex differences were also analyzed. METHOD: Audiometric thresholds were collected from 717 adult participants between the ages of 18 and 88 years (438 female, 279 male) at standard octave and interoctave frequencies between 0.25 and 16 kHz. Of those participants, 62 had repeated audiometric evaluations within 1 year of measurement. Data were analyzed using the equations reported by the 2017 ISO 7029 report and by calculating four-frequency standard and extended high-frequency (EHF) pure-tone averages (PTAs) in alignment with the WHO. RESULTS: = 62), extended high-frequency threshold interclass correlation coefficients showed excellent test-retest reliability. EHF four-frequency PTAs in participants with normal hearing in the standard-frequency range had a wide range of -12.5 to 97.5 dB HL, with potential functional implications. CONCLUSIONS: Adaptation of norms as a single cutoff value or through the use of PTA in the EHF range is feasible due to agreement in the literature and the stability of test-retest measurements. Male extended high-frequency thresholds are poorer than the female's. EHF measurements could provide diagnostic value in outpatient clinical sessions; however, functional hearing deficits are important when considering typical versus atypical thresholds in this range. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.34961473.