Method and apparatus for optically stimulating neurons of a plurality of auditory nerve pathways of a person to provide auditory sensations for the person by generating a plurality of pulsed light signals having one or more successive pulses. The spectrum of a detected audio signal is divided into M channels. In some embodiments, an N-of-M coding strategy is employed, where, for any given time frame, only N of the M channels are selected and illuminated to stimulate the auditory nerves. In some embodiments, the M channels are organized into bins, where, for any given time frame, only a maximum number of channels are illuminated per bin. This limits the number of illuminated channels-per-length of cochlea and therefore prevents localized heating of the cochlea and reduces power consumption of the device.
