Fast frequency selectivity measures in listeners with severe hearing loss

Abstract

Communication difficulties in severe hearing loss are a combination of elevated pure-tone thresholds and suprathreshold deficits; for example, frequency selectivity, which may be substantially impaired in listeners with severe loss. The purpose of this study was to investigate frequency selectivity measures in listeners with severe loss (pure-tone average 60–90 dB HL). Two tests were used: fast psychophysical tuning curves (PTC), in which an intermittent tone was detected during a narrowband noise masker swept continuously in frequency; and spectral ripple (SR), in which the number of sinusoidal ripples in the spectrum of a broadband noise was tracked in an adaptive forced-choice procedure. Results showed that both tests have advantages when evaluating listeners with severe loss. Fast PTC provided a direct representation of tuning in a specific frequency region but was limited by the residual dynamic range of the listener. Dynamic range limitations were partially overcome by combining data from multiple trials. SR was able to be performed by listeners with minimal dynamic range but the interpretation of results was limited by potential differences in hearing across the bandwidth of the stimuli. Both fast PTC and SR revealed information about suprathreshold deficits that could help guide audiological intervention. [Work supported by NIH.]