The influence of compression on behavioral estimates of frequency resolution

This study focuses on the ability of the auditory system to decompose sounds into their individual frequency components. This "frequency resolution" is a fundamental aspect of auditory processing and is known to influence the perception of speech and other ecologically relevant stimuli. Invasive physiological measurements of frequency selectivity are not possible in humans. Thus much of what is known about human frequency resolution comes from studies based in auditory perception. Perceptual studies are likely influenced by the slow or "compressive" growth of the cochlea's basilar membrane as a function of stimulus intensity. Previous studies in frequency resolution have not sought to control for the effects of this "compression." The present study is concerned with developing a perceptual technique for measuring frequency resolution that accounts for the influence of cochlear compression. Preliminary results suggest that compression appreciably influences estimates of frequency resolution and may lead to the interpretation that human frequency resolution is higher than actually present in the cochlea. Implications of these findings suggest that clinical and research estimates of frequency selectivity should be refined to account for the influence of cochlear compression.