Patent attributes
An earpiece includes a feed-forward microphone coupled to the environment outside the headphones, a feedback microphone coupled to an ear canal of a user when the earpiece is in use, a speaker coupled to the ear canal of the user when the earpiece is in use, a digital signal processor implementing feed-forward and feedback noise compensation filters between the respective microphones and the speaker, and a memory storing an ordered sequence of sets of filters for use by the digital signal processor. Each of the sets of filters includes a feed-forward filter that provides a different frequency-dependent amount of sound pass-through or cancellation, which in combination with residual ambient sound reaching the ear results in a total insertion gain at the ear of a user.
