A harmonic-cancellation-based model to predict speech intelligibility against a harmonic masker

This work aims to predict speech intelligibility against harmonic maskers. Unlike noise maskers, harmonic maskers (including speech) have a harmonic structure that may allow for a release from masking based on fundamental frequency (F0). Mechanisms, such as spectral glimpsing and harmonic cancellation, have been proposed to explain F0 segregation, but their relative contributions and ability to predict behavioral data have not been explored. A speech intelligibility model was developed that includes both spectral glimpsing and harmonic cancellation. The model was used to fit the data of two experiments from Deroche, Culling, Chatterjee, and Limb [J. Acoust. Soc. Am. 135, 2873–2884 (2014)], in which speech reception thresholds were measured for stationary harmonic maskers varying in their F0 and degree of harmonicity. Key model parameters (jitter in the masker F0, shape of the cancellation filter, frequency limit for cancellation, and signal-to-noise ratio ceiling) were optimized by maximizing the correspondence between the predictions and data. The model was able to accurately describe the effects associated with varying the masker F0 and harmonicity. Across both experiments, the correlation between data and predictions was 0.99, and the mean and largest absolute prediction errors were lower than 0.5 and 1 dB, respectively.