A room monitoring System is provided, comprising: a speaker; a microphone; and a digital signal processor (DSP) adapted to generate and transmit a first audio test signal to the speaker to be broadcast in the room, wherein the first audio test signal comprises a power spectral density that is inversely proportional to its frequency, and wherein the transmitted first audio test signal is reflected within the room, and wherein the DSP is further adapted to process the reflected broadcast first audio test signal received by the microphone, generate and save a frequency-amplitude analysis of the received first audio test signal as an initial reference curve, periodically test the room in a substantially similar manner to generate one or more additional reference curves, and compare the one or more additional reference curves to determine whether they are within a known, predetermined tolerance of the initial reference curve.

An integrated circuit may include an output for providing a signal to a transducer including both source audio for playback to a listener and an anti-noise signal for countering the effects of ambient audio sounds in an acoustic output of the transducer, a microphone input for receiving a microphone signal indicative of ambient sounds at the transducer, a link control input for receiving link control information of a communications link coupling the integrated circuit to the transducer and/or a microphone for generating the microphone signal, wherein the link control information includes a link quality metric of the communications link, and a processing circuit comprising a filter having a response that generates the anti-noise signal in conformity with the microphone signal to minimize the ambient sounds at the acoustic output of the transducer, wherein the processing circuit modifies generation of the anti-noise signal responsive to the link quality metric.

Provided is an electroacoustic transducer capable of reducing the thickness and weight of the entire pillow when a speaker is embedded in the pillow or a headrest, enabling miniaturization of a device by causing the position of the speaker to be close to a position at which the head is placed, and improving the accuracy of signal processing by reducing a load of the signal processing in a case where active noise control is performed, thereby improving a noise reduction effect. The electroacoustic transducer includes: an electroacoustic transduction unit having an electroacoustic transduction film including a polymer composite piezoelectric body in which piezoelectric body particles are dispersed in a viscoelastic matrix formed of a polymer material having viscoelasticity at a normal temperature and thin film electrodes respectively laminated on both surfaces of the polymer composite piezoelectric body, and an elastic support disposed in close contact with one principal surface to bend the shape of the electroacoustic transduction film; and a first cushion layer that is in contact with the electroacoustic transduction film on an electroacoustic transduction film side of the electroacoustic transduction unit to cover the electroacoustic transduction unit and is formed of a three-dimensional solid knitted fabric.

A hands-free intercom may include a user-tracking sensor, a directional microphone, a directional sound emitter, a display device, and/or a communication interface. The user-tracking sensor may determine a location of a user so the directional microphone can measure vocal emissions by the user and the directional sound emitter can deliver audio to the user. The hands-free intercom may provide privacy to the user. The hands-free intercom may prevent an eavesdropper from hearing the user's vocal emissions, for example, by canceling the vocal emissions at the eavesdropper's ear. The directional sound emitter may deliver out-of-phase sound to cancel the vocal emissions. The hands-free intercom may also, or instead, cancel ambient noise at the user's ear. The hands-free intercom may measure or predict a filtration of the sound to be canceled and compensate for the filtration when canceling the sound.

The overall performance of an ANC system may be improved by configuring the ANC system to perform adaption in the frequency domain. The ANC systems may be configured to update an algorithm of an adaptive filter based, at least in part, on the first input signal, the second input signal, and a feedback signal that is based on an output of the adaptive filter. Updating may include changing parameters of the algorithm based on a SDR based, at least in part, on the first input signal. Updating may also include normalizing a step size and processing at least full band information for the input signal in a frequency domain to generate coefficient values for the algorithm. Updating may also include applying a frequency domain magnitude constraint on adaptive filter coefficients.

The handling of disturbances to audio signals may be improved with an adaptive noise cancellation (ANC) system that performs frequency-domain adaption. The ANC systems may be configured to determine if a disturbance is present at a first frequency in the second input signal received from the reference microphone. The ANC systems may update an algorithm of an adaptive filter based, at least in part, on the first input signal, the second input signal, and a feedback signal that is based on an output of the adaptive filter by changing parameters of the algorithm such that the adaptive filter adapts around the first frequency differently than other frequencies when the disturbance is present.

A phone stand includes a phone holder for coupling to a phone, where the phone is for conducting a voice session. The phone stand further includes a plurality of directional speakers positioned to project sound to a focused audio area corresponding to a location where a user is expected to be positioned, a plurality of back speakers positioned behind the location where the user is expected to be positioned, and a system controller. The system controller is configured to: receive audio signals, where the audio signals includes audio of the voice session from the phone; separate the audio signals into speech signals and non-speech signals; obtain one or more output mixing attributes; generate mixed signals by combining the speech signals and the non-speech signals according to the one or more output mixing attributes; and send the mixed signals to the plurality of directional speakers.

Methods and apparatuses for addressing open space noise are disclosed. In one example, a method for masking open space noise includes receiving a plurality of mobile device microphone data from a plurality of mobile devices. A location data associated with each mobile device in the plurality of mobile devices is received. A plurality of stationary microphone data is received from a plurality of stationary microphones. A sound masking noise output is adjusted at one or more loudspeakers responsive to the plurality of mobile device microphone data and the plurality of stationary microphone data.

Embodiments of the present disclosure provide a noise reduction method, the method includes: obtaining an acceleration signal of a mobile terminal when an audio output device is in a working state; determining, according to the acceleration signal, a vibration waveform of the mobile terminal when the mobile terminal vibrates; inverting the determined vibration waveform to obtain a noise reduction signal; and superimposing the noise reduction signal onto to-be-output audio of the audio output device. Therefore, noise generated by skeleton vibration is diminished or eliminated, so as to improve an effect of listening, by a person, to audio.

A noise cancelation device that programs, records, and saves sounds and noises and their respective sound waves, inverts them, and broadcasts the inverted sound waves, thereby reducing, deadening, canceling, or eliminating, the original sounds and noises, and their respective sound waves. Further, the noise cancelation device can save sounds and noises that have a constant, predictable, steady, and recognizable sound quality and their respective sound waves, and preprogram the respective inverted sound waves, which allows for the noise cancelation device to broadcast the preprogrammed inverted sound waves through speakers to reduce, deaden, or cancel the original sounds and noise when they are present. The noise cancelation device is portable and may be used in any location desired, or the noise cancelation device may be is fixed in its location.