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

Area of Science:

• Audiology
• Neuroscience
• Signal Processing

Background:

• Auditory Steady-State Responses (ASSRs) are crucial for assessing auditory function.
• Objective response detection (ORD) techniques like Spectral F-Test (SFT) and Magnitude Squared Coherence (MSC) are used for ASSR analysis.
• Optimizing stimulus parameters is key to improving ASSR detection rates.

Purpose of the Study:

• To evaluate the performance of Frequency Specific Auditory Steady-State Response (FS-ASSR) detection using a novel amplitude-modulated tone with a 2-order exponential envelope (AM2).
• To compare the efficacy of AM2 with conventional amplitude modulation (AM) using SFT and MSC objective detection techniques.
• To assess the impact of AM2 on ASSR amplitude, detection rate (DR), and detection time across different sound pressure levels (dBSPL) and carrier frequencies.

Main Methods:

• 24 normal-hearing adults participated in the study.
• Binaural multi-tone stimulation with AM and AM2 at 60, 45, and 30 dBSPL was used.
• Carrier frequencies of 500, 1000, 2000, and 4000 Hz were modulated between 77 and 105 Hz.
• Objective response detection techniques, Spectral F-Test (SFT) and Magnitude Squared Coherence (MSC), were employed.

Main Results:

• AM2 elicited significantly higher FS-ASSR amplitudes than AM across all tested dBSPL, with a notable increase at 500 Hz (22.5%).
• AM2 improved the Detection Rate (DR) by up to 8.3% at 500 Hz and 30 dBSPL, particularly beneficial near hearing thresholds.
• Both MSC and SFT showed comparable Detection Rates (DR) and a False Detection Rate (FDR) around 5%.
• High detection rates (>90%) were achieved within 3.5 to 4.9 minutes at higher intensities.

Conclusions:

• The AM2 stimulus offers enhanced FS-ASSR detection compared to conventional AM, particularly at lower intensities and specific frequencies.
• AM2 shows promise for improving audiological assessments, especially for detecting responses near the hearing threshold.
• Further research is needed to explore the application of AM2 in individuals with hearing loss and for efficient multiple FS-ASSR testing.