Patent training audio

The U.S. Patent and Trademark Office has published a patent application from Apple, which relates to a spatial audio rendering processor for AirPods Max, which can calibrate the audio beamforming array processing algorithm to respond to the changes in the physical shape of wearable audio devices. It is not clear whether Apple's patent describes the future development direction of its H 1 chip.

Beamforming is an audio signal processing operation in which a transducer array is used for directional sound transmission or reception. For example, in the case of directional sound reception, usually a microphone array with two or more microphones captures sound and extracts spatial audio information through processing.

For example, in the case where a microphone array picks up multiple sound sources, beamforming allows an audio signal representing one of the multiple sound sources to be extracted. Thereby allowing the microphone array to focus sound pickup on the sound source while attenuating (or filtering) other sound sources.

With respect to directional sound transmission, a speaker array usually having two or more speakers generates a beam pattern to project sound in different directions.

For example, a beamformer may receive an input audio channel of sound program content (e.g., music) and convert the input audio channel into several driving signals to drive the speakers of a speaker array, thereby generating an acoustic beam pattern.

One aspect of Apple's invention is to measure the transfer function of each different physical arrangement of the beamforming array of wearable devices (such as microphone array or speaker array) to consider various shapes of wearable devices.

These measurements can be made in a dedicated anechoic room, where wearable devices are placed and deformed (manipulated) into a given shape.

In order to measure the microphone array, speakers are placed around the wearable device, and each speaker represents a sound source in the acoustic space.

Each speaker generates sound independently so as to measure the transfer function of each microphone in the array for this position of the sound source.

Another aspect of Apple's invention relates to determining the physical arrangement of a beamforming array by using at least one of various methods.

The acoustic method includes measuring a near-field transfer function of at least one audio element of a beamforming array, which represents an acoustic transmission path between the audio element and a known location.

In addition, there are optical methods to associate each physical layout of an array with image data captured by a camera and mechanical sensing methods to associate a given physical layout with mechanical sensing data.

Information from: patentlyapple