Frequency-Specific Audiometry Using Steady-State Responses

TLDR

The study aimed to assess whether steady‑state responses to multiple simultaneous tones amplitude‑modulated at 75–110 Hz could serve as a useful objective audiometric tool. Researchers recorded steady‑state responses to eight concurrently presented tones modulated at 75–110 Hz across a range of intensities in normal adults, well babies, adults with simulated hearing loss, and adolescents with known losses, then compared the resulting thresholds to behavioral measures. The technique produced thresholds within 10–15 dB of behavioral values in normal adults, yielded reliable thresholds in well babies, and correlated strongly (r = 0.70–0.91) with behavioral thresholds in adolescents, demonstrating that the multiple‑stimulus steady‑state response can provide frequency‑specific objective audiometry and estimate eight thresholds simultaneously.

Abstract

Objective: To evaluate the audiometric usefulness of steady-state responses to multiple simultaneous tones, amplitude-modulated at 75 to 110 Hz. Design: Steady-state responses to multiple tones amplitude-modulated at different rates between 75 and 110 Hz and presented simultaneously were recorded at different intensities in normal adults, well babies, normal adults with simulated hearing loss, and adolescents with known hearing losses. Response thresholds were compared with behavioral thresholds. Results: In normal adults the thresholds for steady-state responses to tones of 0.5, 1, 2, and 4 kHz were 14 ± 11, 12 ± 11, 11 ± 8, and 13 ± 11 dB, respectively, above behavioral thresholds for air-conducted stimuli, and 11 ± 5, 14 ± 8, 9 ± 8, and 10 ± 10 dB above behavioral thresholds for bone-conducted stimuli. In well babies tested in a quiet environment, the thresholds were 45 ± 13, 29 ± 10, 26± 8, and 29 ± 10 dB SPL. In adolescents with known hearing losses, the steady-state responses thresholds predict behavioral thresholds with correlation coefficients (r) of 0.72, 0.70, 0.76, and 0.91 at 0.5, 1, 2, and 4 kHz, respectively. Conclusion: Steady-state responses to tones amplitude-modulated at 75 to 110 Hz can be used for frequency-specific objective audiometry. The multiple-stimulus technique allows thresholds to be estimated for eight different stimuli at the same time.