Patent attributes
An implantable neural stimulation system, such as a cochlear implant system, utilizes a Distributed Compression Amplitude Mapping (DCAM) system to distribute signal compression between a pre-bandpass linear mapping function, and a post-bandpass compressive mapping function. The pre-bandpass linear mapping function is implemented, in one exemplary embodiment, as a traditional audio compressor to prevent distortion that might result from a non-linear mapping function. The post-bandpass compressive mapping function is implemented, in another exemplary embodiment, as a logarithmic transform to reflect natural hearing. As a result of the DCAM processing, the differences in amplitudes of components of the acoustic spectrum are maintained. By maintaining these differences, spectral smearing between channels is reduced and speech clues are preserved.
