A method for active noise reduction in an electric or hybrid vehicle includes (i) detecting noise in an area surrounding the vehicle by at least one sound recording apparatus which is attached to the vehicle, and (ii) generating anti-phase sound by at least one sound output apparatus, which is attached to the vehicle, depending on a signal recorded by the sound recording apparatus. The generated anti-phase sound is generated with respect to a portion of the noise in the area surrounding the vehicle and is output into the area surrounding the vehicle. Also described is a corresponding electric or hybrid vehicle which is designed to perform active noise reduction with respect to its ambient noise.

Noise abatement within a signal stream containing unwanted signal referred to as noise is performed by acquiring a digitized noise signal and using a digital processor circuit to subdivide the acquired noise signal into different frequency band segments and thereby generate a plurality of segmented noise signals. Then individually for each segmented noise signal, the processor shifts in time the segmented noise signal by an amount dependent on a selected frequency of the segmented noise signal to produce a plurality of shifted segmented noise signals. The precise time shift applied to each noise segment considers the frequency content of the segment and the system processing time. Individually for each segmented noise signal, amplitude scaling is applied. The shifted and amplitude-scaled segmented noise signals are then combined to form a composite anti-noise signal which is output into the signal stream to abate the noise through destructive interference.

[Object] There is proposed a mechanism that allows for a higher noise cancellation effect by operating a plurality of units in coordination. [Solution] An information processor including a signal processing section that: acquires a first signal to be detected by an acoustic input section of a first unit including the acoustic input section disposed within a predetermined distance from one ear hole of a user in a state of being worn by the user; acquires a second signal, which indicates a noise generated from a noise source, to be acquired by a second unit; and generates a noise cancellation signal directed to the noise on the basis of the first signal and the second signal.

An earpiece includes a feed-forward microphone coupled to the environment outside the headphones, a feedback microphone coupled to an ear canal of a user when the earpiece is in use, a speaker coupled to the ear canal of the user when the earpiece is in use, a digital signal processor implementing feed-forward and feedback noise compensation filters between the respective microphones and the speaker, and a memory storing an ordered sequence of sets of filters for use by the digital signal processor. Each of the sets of filters includes a feed-forward filter that provides a different frequency-dependent amount of sound pass-through or cancellation, which in combination with residual ambient sound reaching the ear results in a total insertion gain at the ear of a user.

A noise cancellation system with harmonic filtering for a vehicle audio system may include at least one input sensor configured to transmit reference signals, and at least one input sensor configured to transmit at least two narrowband input signals each of the input signals including harmonic noise. The system may include a processor being programmed to receive the reference signals, the reference signals including at least two narrowband reference signals, receive the narrowband input signals, apply a gain reference control to the reference signals to determine whether the frequencies of each of the reference signals are within a predefined range of another, and remove one of the reference signals in response to the frequencies of each of the reference signals being within the predefined range of another to prevent common harmonic content from presiding on both reference signals during the algorithm adaption.

[Object] To provide a structure that can effectively reduce a noise containing a component varying in characteristic.

[Solution] A signal processing apparatus including: a signal processing section configured to generate a first noise reduction signal using an adaptive filter on the basis of a signal output from a first input apparatus, and cause the generated first noise reduction signal to be output by a first output apparatus, and generate a second noise reduction signal using a fixed filter on the basis of a signal output from a second input apparatus, and cause the generated second noise reduction signal to be output by a second output apparatus.

A noise cancellation system with harmonic filtering for a vehicle audio system may include at least one input sensor configured to transmit reference signals, at least one input sensor configured to transmit a narrowband input signal and a broadband input signal, each of the narrowband input signal and broadband input signal including harmonic noise. The system may include a processor being programmed to receive the reference signals, the reference signals including a narrowband reference signal and a broadband reference signal, apply an adaptive filter to each of the reference signals, apply a secondary path to the input signals to generate antinoise signals, sum the antinoise signals broadcast over the secondary path and the primary noise signals to generate an error signal at the output sensor, and apply an adaptive filter to the error signal to remove harmonic noise to prevent cancelation of the harmonic noise.

An earpiece includes a feed-forward microphone coupled to the environment outside the headphones, a feedback microphone coupled to an ear canal of a user when the earpiece is in use, a speaker coupled to the ear canal of the user when the earpiece is in use, a digital signal processor implementing feed-forward and feedback noise compensation filters between the respective microphones and the speaker, and a memory storing an ordered sequence of sets of filters for use by the digital signal processor. Each of the sets of filters includes a feed-forward filter that provides a different frequency-dependent amount of sound pass-through or cancellation, which in combination with residual ambient sound reaching the ear results in a total insertion gain at the ear of a user.

Embodiments include systems with active sound canceling properties, fenestration units with active sound canceling properties, retrofit units with active sound canceling properties and related methods. In an embodiment a system can include a sound cancellation device include a sensing element to detect vibration of a transparent pane and/or a sound input device configured to detect sound incident on the transparent pane, as well as a vibration generator configured to vibrate the transparent pane and a sound cancellation control module. The sound cancellation control module can evaluate the detected vibration of the transparent pane at two or more discrete frequency bands. The sound cancellation control module can cause the vibration generator to vibrate the transparent pane causing destructive interference with sound waves at the two or more discrete frequency bands. Other embodiments are also included herein.

The headset includes an electro-acoustic transducer, at least one noise reduction processing chain including external and internal microphones, a processing filter including mounted in parallel between the external microphone and an adder, at least one elementary filter each including a recursive filter and an elementary variable gain amplifier, a control unit for the gain of each elementary amplifier according to a signal coming from the external microphone and an error signal coming from the internal microphone.

The processing filter includes an open-loop main filter connected at the input to the external microphone and the output of which is connected, to the adder, and to the input of the or each elementary filter.