Probing cochlear compressive nonlinearity using signal-to-noise ratio-optimized distortion product otoacoustic...

Area of Science:

• Auditory Neuroscience
• Otoacoustic Emissions
• Nonlinear Auditory Physiology

Background:

• Cochlear compression is vital for processing sound dynamics.
• Distortion product otoacoustic emissions (DPOAEs) offer non-invasive assessment of cochlear compression.
• Low signal-to-noise ratio (SNR) in DPOAE measurements, particularly at low levels, limits accuracy.

Purpose of the Study:

• To investigate a novel peak-based method for DPOAE input/output (i/o) function measurement.
• To enhance the reliability and robustness of cochlear compression estimates.
• To compare the peak-based method with the conventional approach for DPOAE measurement.

Main Methods:

• DPOAE i/o functions were derived using two methods: conventional f2 frequencies and a peak-based approach targeting high-SNR maxima.
• A two-segment piecewise linear fit modeled DPOAE i/o functions to estimate slopes and compression thresholds.
• Repeatability was assessed using intraclass correlation coefficient and Bland-Altman analysis.

Main Results:

• The peak-based method demonstrated significantly higher SNR and DPOAE levels compared to the conventional method.
• Reliability analyses confirmed that the peak-based approach provided more consistent and repeatable estimates of cochlear compression.
• The findings highlight improved measurement quality with the peak-based targeting strategy.

Conclusions:

• The peak-based method offers a more robust and reliable approach for estimating cochlear compression via DPOAEs.
• Targeting fine-structure peaks in DPOAE measurements enhances data quality, especially at lower stimulus levels.
• This technique holds promise for improved non-invasive assessment of auditory function.