Patent ID: 7916823

Claim:
A method for “listening in” on what a cochlear implant patient is hearing as the patient uses his or her cochlear implant system, the method comprising: playing back an audio signal stream at a dynamically-adjustable synchronous rate, the audio signal stream being received within an audio processor of the cochlear implant system and being processed along an audio signal processing path within the audio processor, wherein the audio processor includes analog front end circuitry and digital signal processing circuitry; coupling a mixed-mode phase locked loop system to at least one tap point of a multiplicity of tap points located along the audio signal processing path within the digital signal processing circuitry; coupling the mixed-mode phase locked loop system to a fitting station used with the cochlear implant system when fitting the cochlear implant system to the patient; and using the mixed-mode phase locked loop system for “listening” on what the patient is hearing through his or her cochlear implant system by: receiving digital audio samples of the audio signal stream from the tap points within the digital signal processing circuitry of the audio processor at a consistent, but unknown, average rate; extracting the average sample rate; generating a local clock signal at the average sample rate; and re-synchronizing the digital audio samples to the local clock signal when audio playback of the audio signal stream is desired in order to “listen in” on what the patient is hearing.