Systems and methods are described to extract desired audio from an apparatus to be worn on a user's wrist. The apparatus includes a wrist wearable device, configured to be worn on the user's wrist. The wrist wearable device includes a first microphone. The first microphone has a first response pattern. The first microphone is coupled to the wrist wearable device. The first microphone is positioned on the wrist wearable device to receive a voice signal from a user when the wrist wearable device is on the user's wrist.

A person support apparatus, such as a bed, cot, stretcher, or the like, includes an active noise cancellation device configured to generate a noise cancelling sound wave that is designed to cancel a noise sound wave. The active noise cancellation device may include speakers and a microphone. In other embodiments, the person support apparatus includes a sound emitting component and a transmitter adapted to send out a notification signal prior to activation of the sound emitting component. The notification signal provides information about a characteristic of the sound to be emitted by the sound emitting device. The recipient of the notification signal may then use the signal to cancel the sound that is to be emitted. In some embodiments, the person support apparatus acts as a conduit for notification signals of upcoming sounds, receiving and forwarding such notification signals from and to other devices.

The application describes techniques for howling detection. A howling detector is described that is configured to receive an input signal and to determine measure of the linearity of a logarithmic representation of the energy of the input signal. In some examples, this triggers gain adjustment (e.g. of a noise control unit) and, in some further examples, the amount of the gain adjustment may be based on an estimation of the maximum stable gain of a noise control unit.

Embodiments of the present invention provide a vehicle privacy system (700), comprising audio input means (130, 190, 720) for receiving an external audio signal (725) indicative of audio from within a vehicle (900), audio source means (710, 910) for receiving the external audio signal (725) and determining an output audio signal (735) in dependence thereon for reducing an external intelligibility of speech within the vehicle (900), and audio output means (145, 146, 147, 730, 920) for receiving the output audio signal (735) and outputting audio (925) corresponding thereto to be at least partly audible external to the vehicle (900).

An audio processing system is described including an amplifier configured to receive a first audio signal and output the first audio signal to an acoustic transducer comprising a voice coil. A sensor detects a signal corresponding to voice coil current of the acoustic transducer. A controller compares the first audio signal and the detected signal and determines a second audio signal from the comparison. The second audio signal is representative of an external sound source detected via the acoustic transducer. The audio processing system may simultaneously output the first audio signal and receive the second audio signal using the same acoustic transducer.

An audio noise calibration circuit is provided comprising: a speaker, the speaker including a driver input; a switch having a first terminal, a second terminal, and an output, and wherein the switch is adapted to be responsive to a switching signal having at least a first switching state and a second switching state such that the first terminal of the switch is connected to the output of the switch when the switching signal is in the first switching state such that there is electrical connectivity between the first terminal and the output, and the second terminal of the switch is connected to the output of the switch when the switching signal is in the second switching state such that there is electrical connectivity between the second terminal and the output, and further wherein the output of the switch is connected to the driver input of the speaker; and an audio processing unit adapted to generate the switching signal such that when in the first switching state, an audio signal generated by the audio processing unit is transferred to the first terminal and then to the driver input of the speaker to be broadcast, generate the switching signal such that when in the second switching state, the driver input of the speaker is connected to a first portion of the audio processing unit such that the speaker operates as a microphone to acquire ambient noise sound, and an electrical output of the microphone that represents the ambient noise sound is processed by the first portion of the audio processing unit to generate a digitized ambient noise sound, and modify a next output audio signal based on the digitized ambient noise sound.

A method performed by a wearable audio output device worn by a user is provided for controlling external noise attenuated by wearable audio output device. A speech is detected from a user wearing the wearable audio output device, wherein the audio output device has active noise reduction turned on. It is determined, based on the detecting, that the user desires to speak to a subject in the vicinity of the user. In response to the determining, a level of noise reduction is reduced to enable the user to hear sounds external to the audio output device. It is determined that the user desires to speak to the subject by detecting at least one condition of a plurality of conditions.

Sound reduction includes producing an error signal representative of sound present in a target space, producing a reference signal corresponding to undesired sound present in the target space, and producing, based on the reference signal and the error signal a cancelling signal representative of the undesired sound present in the target space. Sound reduction further includes producing, based on the cancelling signal, sound to destructively interfere with the undesired sound present in the target space, producing sound based on an audio signal in the target space, and removing from the reference signal, based on the audio signal, a reference signal component representative of audio signal components transferred via a feedback path from the transducer to the reference sensor.

A speakerphone system is provide, comprising: at least one mechanical vibration sensor (MVS) adapted to convert mechanical vibrations in a speakerphone enclosure (enclosure) to a mechanical vibration error signal, and output the same as an MVS output signal; at least one microphone (mic) adapted to convert an input sound acoustic signal into an input sound electrical signal and to output the same as a mic output signal; and circuitry adapted to subtract the MVS output signal from the mic output signal and output the resultant signal as a speakerphone output signal.

A method for substantially eliminating the effect of mechanical vibration on an audio input to a speakerphone system is provided herein, the method comprising: receiving an input sound acoustic signal at a microphone (mic); converting the received input sound acoustic signal into an input sound electrical signal, and outputting the same as a mic output signal; receiving mechanical vibrations at a mechanical vibration sensor (MVS); converting the received mechanical vibrations into a mechanical vibration error signal, and outputting the same as an MVS output signal; and generating a speakerphone system output signal by subtracting the MVS output signal from the mic output signal.