This repository contains code that implements a sine wave vocoder for simulating the sound quality of a cochlear implant (CI). The traditional sine wave vocoder models the limited spectral information available to a CI user by summing together sine waves at frequencies that correspond to the electrode channels of a CI. In CI users, the effective spectral resolution is limited by channel interactions, a psychophysical phenomenon where the electrical stimulation on one electrode channel influences the perception of a stimulus presented on an adjacent channel.
This code simulates a CI with channel interaction. Channel interaction is simulated as a weighted sum of analysis band envelopes across different frequency bands. Note that the current code assumes the ACE CI processing strategy as implemented in the Nucleus MATLAB Toolbox.
The main function to run is generateVocodedSpeechWithCurrentSpread.m. This function takes the following input arguments:
- p: CI processing map
- y: sine wave vocoded signal without channel interactions
- filter_slope: controls the amount of channel interaction