HEADPHONES USING MULTIPLEXED MICROPHONE SIGNALS TO ENABLE ACTIVE NOISE CANCELLATION

摘要

Headphones or a headset to enable active noise cancellation or binaural recording. Microphone signals are multiplexed within the headphones/headset and are conveyed to an attached device using a single contact point in the audio plug. The audio plug may be a conventional four connector audio plug to provide backwards compatibility. The multiplexing is analog multiplexing, and may be time-domain or frequency-domain multiplexing.

主权项

1. Headphones to enable active noise cancellation, comprising:
left and right speakers contained in left and right speaker housings; at least one microphone in the left speaker housing and at least one microphone in the right speaker housing, each microphone producing a respective microphone signal; an analog multiplexer for multiplexing the respective microphone signals into a combined signal; and a multi-wire cord having a ground wire, a left speaker signal wire coupled to the left speaker, a right speaker signal wire coupled to the right speaker, and a microphone output wire coupled to the analog multiplexer to receive the combined signal, wherein the multi-wire cord terminates in an audio plug, and wherein the analog multiplexer is coupled to one of the left speaker signal wire or the right speaker signal wire to receive a frequency signal extracted from a speaker signal, and wherein the multiplexer multiplexes the respective microphone signals into the combined signal under control of a frequency of the frequency signal supplied by the speaker signal.