Assessment of frequency specific auditory steady-state response using amplitude modulation with 2-order exponential envelope

This study investigated the performance of Frequency Specific Auditory Steady-State Response (FS-ASSR) detection elicited by the amplitude modulated tone with 2-order exponential envelope (AM²), using objective response detection (ORD) techniques of Spectral F-Test (SFT) and Magnitude Squared Coherence (MSC). ASSRs from 24 normal hearing adults were obtained during binaural multi-tone stimulation of amplitude-modulation (AM) and AM² at intensities of 60, 45 and 30 dB_SPL. The carrier frequencies were 500, 1000, 2000, and 4000 Hz, modulated between 77 and 105 Hz. AM² achieve FS-ASSR amplitudes higher than AM by 16%, 18% and 12% at 60, 45 and 30 dB_SPL, respectively, with a major increase at 500 Hz (22.5%). AM^S2PL increased the Detection Rate (DR) up to 8.3% at 500 Hz for 30 dB_SPL, which is particularly beneficial for FS-ASSR detection near the hearing threshold. In addition, responses in 1000 and 4000 Hz were consistently increased. The MSC and SFT presented no differences in Detection Rate (DR). False Detection Rate (FDR) was close to 5% for both techniques and tones. Detection times to reach DR over 90% were 3.5 and 4.9 min at 60 and 45 dB_SPL, respectively. Further investigation concerning efficient multiple FS-ASSR is still necessary, such as testing subjects with hearing loss.