The effect of presentation level on spectrotemporal modulation detection

Abstract

Abstract The understanding of speech in noise relies (at least partially) on spectrotemporal modulation sensitivity. This sensitivity can be measured by spectral ripple tests, which can be administered at different presentation levels. However, it is not known how presentation level affects spectrotemporal modulation thresholds. In this work, we present behavioral data for normal‐hearing adults which show that at higher ripple densities (2 and 4 ripples/oct), increasing presentation level led to worse discrimination thresholds. Results of a computational model suggested that the higher thresholds could be explained by a worsening of the spectrotemporal representation in the auditory nerve due to broadening of cochlear filters and neural activity saturation. Our results demonstrate the importance of taking presentation level into account when administering spectrotemporal modulation detection tests. HighlightsSpectrotemporal modulation thresholds worsened with increasing level.Auditory filters broadening deteriorated spectrotemporal modulation discrimination.A computational model allowed insight into behavioral data.Higher thresholds were caused by the detriment of the peripheral representation.A fixed presentation level should be used when measuring spectrotemporal sensitivity.