Apple has been granted a patent (number 9,516,442) to improve the audio quality of earbuds used with smartphones, tablets, laptops, and desktop computers. The company says that under typical environmental conditions, the microphones in eabudds may do a poor job of capturing a sound of interest (e.g., speech received from a user's mouth) due to the presence of various background sounds.
To address this issue many audio devices often rely on noise reduction, suppression, and/or cancellation techniques. One commonly used technique to improve signal to noise ratio is audio beamforming. Audio beamforming is a technique in which sounds received from two or more microphones are combined to enable the preferential capture of sound coming from certain directions.
An audio device that uses audio beamforming can beamform using two or more closely spaced, omnidirectional microphones linked to a processor. The processor can then combine the signals captured by the different microphones to generate a single output to isolate a sound from background noise.
The patent provides technology for determining whether the speaker earbuds of a headset are positioned in a user's ears. The headset may be a "Y" shaped headset with two earbuds having speakers and a plug for insertion into a jack of the audio device. Multiple microphones are located on wired lengths to the earbuds and a common wire between the lengths and the plug, to receive speech from the user's mouth.
Each earbud may have a front and rear microphone, and an accelerometer. Embodiments can detect user speech vibrations at one or more of the microphones, and in the accelerometers in the earbuds. Based on these detections, it can be determined whether one or both of the earbuds are in user's ears. To provide more accurate beamforming, when only one of the earbuds is in the user's ears, only the microphones leading to that earbud are selected for beamforming input.
Apple files for — and is granted — lots of patents by the U.S. Patent & Trademark Office. Many are for inventions that never see the light of day. However, you never can tell which ones will materialize in a real product.