Contribution
Simulating Relative Masking Levels for Narrowband Chirp Stimuli using the Computational Auditory Signal Processing and Perception (CASP) Model
* Presenting author
Abstract:
In brainstem evoked response audiometry, it is sometimes necessary to mask the stimulus in the contralateral ear to prevent cross hearing. Psychoacoustic data of relative masking levels (i.e. the level of the noise necessary to mask the stimulus relative to the stimulus level) of narrowband (NB) chirp stimuli in the presence of a broadband noise masker were presented at the last DAGA [Hots, Knauth, Verhey, Rahne; DAGA 2024]. The present study compares the experimental data to the predictions of the computational auditory signal processing and perception (CASP) model as an established model for auditory masking phenomena. The CASP model consists of several preprocessing stages such as an outer and middle ear filter, a dual-resonance non-linear filterbank, an inner hair cell transduction stage, an adaption stage and a modulation filterbank. The final stage is an optimal detector that compares the internal representation of the current signal with the internal representation of a supra-threshold template. In general, the predictions agree reasonably well with the experimental data. By varying the model parameters, it is shown which cues are used by the model to predict the data.