A signal processing arrangement for a cochlear implant system is described. A sensing microphone senses an acoustic signal to generate a corresponding electrical sound signal. An information detection circuit performs spectral analysis on the sound signal to identify the presence of speech information. A sound signal processing circuit generates an implant communications signal for the cochlear implant system based on the sound signal, and has an energy saving operational mode wherein the implant communications signal is generated only when the information detection circuit identifies that speech information is present in the sound signal.