Aspects of the subject technology relate to a device including a microphone, a filter and a processor. The filter receives an audio signal including ambient noise and a voice of a user of the device from the microphone. At least a portion of ambient noise is filtered from the audio signal. The processor determines a level of the ambient noise in the received audio signal and dynamically adjusts a gain applied to the filtered audio signal based on the level of the ambient noise.

A voice control system and a voice control method for an automatic door are provided. The voice control system includes a sound detection device, a storage device, a first determination circuit, a second determination circuit and a control circuit. The sound detection device detects a sound signal of a sound source, the storage device includes a voiceprint database that includes reference voiceprint features. The first determination circuit analyzes a voiceprint feature of the sound signal and compares the voiceprint feature with the reference voiceprint features. The second determination circuit determines whether a velocity of the sound source falls within a reference speed range according to a frequency variation of the sound signal that matches one of the voiceprint features. In response to the velocity of the sound source within the reference speed range, the control circuit controls the automatic door to be in an open state.

The improved active noise cancellation system for forced air heating or cooling systems onboard aircraft employs a duct having a proximal end coupled to the fan unit to entrain the airflow stream in the direction of a distal end of the duct. A reference sensor is positioned within the proximal end of the duct. A means is provided for injecting an audio frequency control signal into the airflow stream in a manner that does not substantially impede the airflow stream. An error sensor is positioned at the distal end of the duct where it is responsive to sounds carried by the airflow stream, including the audio frequency control signal. An electronic circuit coupled to the reference sensor and to the error sensor supplies a noise abating control signal to energize the control transducer and thereby substantially reduce at least one noise harmonic of the fan unit through destructive interference.

Aspects of the subject technology relate to a device including a microphone, a filter and a processor. The filter receives an audio signal including ambient noise and a voice of a user of the device from the microphone. At least a portion of ambient noise is filtered from the audio signal. The processor determines a level of the ambient noise in the received audio signal and dynamically adjusts a gain applied to the filtered audio signal based on the level of the ambient noise.

An acoustic output device according to an embodiment includes: a housing (520) one or more outward microphones (100) provided in the housing toward an outside of the housing; and two or more drivers (140(1)-(L)) that are provided inside the housing and each of which generates an acoustic control sound based on an acoustic control signal. Furthermore, in a method of controlling an acoustic output device according to an embodiment, the method includes: a processor (300a), causing each of two or more drivers provided inside a housing on which one or more microphones are provided toward an outside to generate an acoustic control sound based on an acoustic control signal.

The improved active noise cancellation system for forced air heating or cooling systems onboard aircraft employs a duct having a proximal end coupled to the fan unit to entrain the airflow stream in the direction of a distal end of the duct. A reference sensor is positioned within the proximal end of the duct. A means is provided for injecting an audio frequency control signal into the airflow stream in a manner that does not substantially impede the airflow stream. An error sensor is positioned at the distal end of the duct where it is responsive to sounds carried by the airflow stream, including the audio frequency control signal. An electronic circuit coupled to the reference sensor and to the error sensor supplies a noise abating control signal to energize the control transducer and thereby substantially reduce at least one noise harmonic of the fan unit through destructive interference.

The improved active noise cancellation system for forced air heating or cooling systems onboard aircraft employs a duct having a proximal end coupled to the fan unit to entrain the airflow stream in the direction of a distal end of the duct. A reference sensor is positioned within the proximal end of the duct. A means is provided for injecting an audio frequency control signal into the airflow stream in a manner that does not substantially impede the airflow stream. An error sensor is positioned at the distal end of the duct where it is responsive to sounds carried by the airflow stream, including the audio frequency control signal. An electronic circuit coupled to the reference sensor and to the error sensor supplies a noise abating control signal to energize the control transducer and thereby substantially reduce at least one noise harmonic of the fan unit through destructive interference.

The improved active noise cancellation system for forced air heating or cooling systems onboard aircraft employs a duct having a proximal end coupled to the fan unit to entrain the airflow stream in the direction of a distal end of the duct. A reference sensor is positioned within the proximal end of the duct. A means is provided for injecting an audio frequency control signal into the airflow stream in a manner that does not substantially impede the airflow stream. An error sensor is positioned at the distal end of the duct where it is responsive to sounds carried by the airflow stream, including the audio frequency control signal. An electronic circuit coupled to the reference sensor and to the error sensor supplies a noise abating control signal to energize the control transducer and thereby substantially reduce at least one noise harmonic of the fan unit through destructive interference.

A method for processing an audio signal is performed at a computing device. The method includes the following steps: receiving a digital stereo audio input signal; extracting localization cues from the digital stereo audio input signal; generating a left-side component and a right-side component from the digital stereo audio input signal, at least partially, in accordance with the localization cues; performing crosstalk cancellation to the left-side component and the right-side component, respectively, to obtain a crosstalk-cancelled left-side component and a crosstalk-cancelled right-side component; and generating a digital stereo audio output signal including the crosstalk-cancelled left-side component and the crosstalk-cancelled right-side component.

A method for processing an audio signal is performed at a computing device. The method includes the following steps: receiving a digital stereo audio input signal; extracting localization cues from the digital stereo audio input signal; generating a left-side component and a right-side component from the digital stereo audio input signal, at least partially, in accordance with the localization cues; performing crosstalk cancellation to the left-side component and the right-side component, respectively, to obtain a crosstalk-cancelled left-side component and a crosstalk-cancelled right-side component; and generating a digital stereo audio output signal including the crosstalk-cancelled left-side component and the crosstalk-cancelled right-side component.