Signal coding for cochlear implants: The effects of pulse width

Biphasic current pulses are used in cochlear implants to code important features of acoustic signals. The duration (width) of each pulse has been used as one of the electrical parameters which code acoustic intensity (and thus loudness). Our psychophysical experiments show that altering the pulse width causes changes in perception other than loudness, that may be the result of changes to the population of activated neurons or its spatial pattern. Thus, pulse width may be one feature which can be utilised in future signal processing strategies in order to more finely manipulate the perception of important features of speech.