#$%^&*AU2009101368A420130221.pdf#####ABSTRACT 2009101368: A method comprising: dividing an audio signal into a plurality of analysis channels; generating one or more tonality indices each representing a tonality of one of said analysis channels; generating one or more stimulation pulses configured to represent said audio signal in accordance with one or more stimulation parameters; and adjusting at least one of said stimulation parameters based on at least one of said tonality indices.