Example techniques may involve performing aspects of a spatial calibration. An example implementation may include detecting a trigger condition that initiates calibration of a media playback system including multiple audio drivers that form multiple sound axes, each sound axis corresponding to a respective channel of multi-channel audio content The implementation may also include causing the multiple audio drivers to emit calibration audio that is divided into constituent frames, the multiple sound axes emitting calibration audio during respective slots of each constituent frame. The implementation may further include recording the emitted calibration audio. The implementation may include causing delays for each sound axis of the multiple sound axes to be determined, the determined delay for each sound axis based on the slots of recorded calibration audio corresponding to the sound axes and causing the multiple sound axes to be calibrated.

An audio notification system for an autonomous vehicle (AV) determines that the AV is within range of a user and emits a sound though a speaker of the AV to notify that the user that the vehicle has arrived. The audio notification system may include a sensor for sensing that the user has accessed the AV, and turns off the sound in response to the user accessing the AV. The audio notification may be generated according to one or more audio options, e.g., volume, pitch, or audio pattern.

A method for determining the directional frequency response of an arrangement of transducer elements. The method comprises providing a simulation of locations of the transducer elements, in the spatial domain; providing a beamforming direction and a frequency range; converting the simulation of locations from the spatial domain into corresponding frequency response values in a spatial frequency domain, such that, for each frequency of a plurality of frequencies in the frequency range, a spatial frequency contour is defined, each of the spatial frequency contours intersecting at the origin; determining the frequency response by applying a transformation to the frequency response values for the provided beamforming direction and frequency range, translating the spatial frequency domain into a modified frequency domain, wherein the contours avoid intersecting; and outputting the frequency response. There is further provided a data processing device adapted to perform the method, a computer program, and a computer-readable medium.

Example techniques may involve performing aspects of a spatial calibration. An example implementation may include detecting a trigger condition that initiates calibration of a media playback system including multiple audio drivers that form multiple sound axes, each sound axis corresponding to a respective channel of multi-channel audio content The implementation may also include causing the multiple audio drivers to emit calibration audio that is divided into constituent frames, the multiple sound axes emitting calibration audio during respective slots of each constituent frame. The implementation may further include recording the emitted calibration audio. The implementation may include causing delays for each sound axis of the multiple sound axes to be determined, the determined delay for each sound axis based on the slots of recorded calibration audio corresponding to the sound axes and causing the multiple sound axes to be calibrated.

A sound field control system SY according to the present invention is provided with: a signal supply unit 210 which supplies a test signal sequence to a speaker; and an analysis unit 150 which picks up a sound including a test sound sequence emitted from a speaker based on a test signal sequence using a microphone, and which determines the sound pickup time of an initial test sound among test sounds included in the test sound sequence, wherein the analysis unit 150 detects the initial sound from the sound pickup signal picked up using the microphone, determines whether a sound is detected after the elapse of a sound emission interval, from the sound pickup time of the detected initial sound, between the initial test sound defined by the test signal sequence and an n-th (where n is an integer such that n≧2) test sound emitted from the same speaker as the initial test sound, and, upon determining that the sound has been detected, determines the sound pickup time of the initial sound as the sound pickup time of the initial test sound.

A system and processes for a proximate-speaker audio compensation system include a first speaker and a second speaker that are proximate to a user. A control unit couples to at least one of the first speaker or the second speaker. The control unit adjusts audio signal based on a hearing-aid type adjustment. The control unit sends adjusted audio signal to the at least one of the first speaker or the second speaker.

A method for self-calibrating a sound pickup process that uses a microphone array in a wearable device that also includes a loudspeaker, where the microphone array being in a physical arrangement with respect to the loudspeaker. The method obtains, for each of several microphones of the microphone array, one or more transfer functions that each represent a response of the microphone to sound from a position in an acoustic space. The method determines whether a physical arrangement of the microphone array with respect to the loudspeaker has changed and adjusts the transfer function, for at least one of the microphones of the several microphones, in response to determining that the current physical arrangement of the microphone array with respect to the loudspeaker has changed.

This accessory is apparatus capable of implementing a method that can affect one or more features of a portable electronic device when brought into a vehicle having a radio with a right and left speaker. The accessory has a sender for initiating transmission of an RF test signal at the portable electronic device. The RF test signal is arranged to cause the radio to produce a distinct pair of audio responses from the right and left speaker. The accessory has a discriminator for determining for the right and left speaker the corresponding return delay between transmission of the RF test signal and arrival of the distinct pair of audio responses at the portable electronic device.

A host device is connected via universal serial bus (USB) connections to one or more external devices with respective speakers. The host device synchronizes playback of audio through the speakers of the USB-connected external devices by requiring devices to implement a deterministic latency between receipt of a start playback request, and requiring devices to slave their audio clocks to USB start-of-frame tokens, and determining a buffered start time for starting data transmission to the respective USB devices. The buffered time equates to the current time of the USB host plus an additional time buffer. The host device waits until the buffered start time, and then starts transmitting the audio stream to the external devices, which, in turn, begin playing the audio data on the next available clock cycle, frame, or microframe.

The subject disclosure is directed towards calibrating sound pressure levels of speakers to determine desired attenuation data for use in later playback. A user may be guided to a calibration location to place a microphone, and each speaker is calibrated to output a desired sound pressure level in its current acoustic environment based upon the attenuation data learned during calibration. During playback, the attenuation data is used. Also described is testing the setup of the speakers, and dynamically adjusting the attenuation data in real time based upon tracking the listener's current location.