Patent ID: 8649526

Claim:
An earphone device comprising; a housing having a proximate end configured for insertion into a user's ear, and a distal end located opposite the proximate end and configured for placement near an outer portion of the user's ear; a speaker configured and arranged to generate sound based upon an audio signal for passing into the user's ear canal via the proximate end of the housing; a microphone at the distal end and configured to detect ambient noise and to detect portions of the generated sound leaked from inside the user's ear canal, with the proximate end of the housing inserted into the ear; and a noise reduction circuit configured to generate a forward leakage transfer function for estimating noise entering the user's ear canal, based upon the detected leaked portions of the generated sound, process a signal corresponding to the detected ambient noise with the forward leakage transfer function to generate and output a noise-cancellation signal to cancel at least a portion of the ambient noise that passes into the user's ear canal.