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.

In the method according to the invention for active noise suppression, a transfer function for a secondary path between a loudspeaker and an error microphone is measured (20). Based on the measured transfer function for the secondary path, a transfer function for a primary path between a reference microphone and the error microphone is estimated (21). Based on the estimated transfer function for the primary path, filter coefficients for filtering to generate the cancellation signal are then determined (22).

An active noise reduction system includes a reference signal generator configured to generate a reference signal, a canceling sound generator configured to generate a canceling sound, an error detector configured to detect an error between a noise and the canceling sound and generate an error signal corresponding to the error, and a controller configured to control the canceling sound generator based on the reference signal and the error signal, wherein the controller is configured to update an estimation value of acoustic characteristics in an internal space of a mobile body based on the reference signal and the error signal, estimate a head position of an occupant in the internal space based on the updated estimation value of the acoustic characteristics, and update a control filter based on the estimated head position of the occupant, the control filter being a filter for controlling the canceling sound generator.

The sound suppression apparatus comprises a sound sensing device, configured to sense a sound; and a sound producing device comprising an air-pulse generating device, configured to generate a plurality of air pulses at an ultrasonic pulse rate. The plurality of air pulses at the ultrasonic pulse rate forms an anti-sound. The anti-sound comprises a component which is configured to suppress the sound.

A controller for an adaptive noise canceling (ANC) system simplifies the design of a stable control response by making the ANC gain of the system independent of a secondary path extending from a transducer of the ANC system to a sensor of the ANC system that measures the ambient noise. The controller includes a fixed filter having a predetermined fixed response, and a variable filter coupled together. The variable response filter compensates for variations of a transfer function of a secondary path that includes at least a path from a transducer of the ANC system to a sensor of the ANC system, so that the ANC gain is independent of the variations in the transfer function of the secondary path.

Automatic noise-reduction (ANR) headsets include circuitry that cancels or suppress undesired noises. Recent years have seen the emergence of in-the-ear (ITE) earphones that incorporate ANR technology; however, designing them to function well usually entails many design tradeoffs, such as using larger ear nozzles that are uncomfortable to obtain desired noise reduction or that require added structures to hold the earphones to a user ear. To avoid these tradeoffs, the present inventors devised, among other things, an exemplary ITE ANR earphone that places its error measurement microphone in the ear nozzle that connects the driver front acoustic volume to a user ear canal. This placement allows use of a narrower more comfortable ear nozzle without compromising noise reduction and without requiring added holding structures. Moreover, the narrower ear nozzle also lowers the likelihood that the ANR circuitry will become unstable and produce undesirable noise.

A loudspeaker arrangement comprises a first loudspeaker configured to radiate an acoustical signal, and a first microphone that is acoustically coupled to the first loudspeaker via a secondary path and that is electrically coupled to the first loudspeaker via an active noise control processing unit. During the use of the loudspeaker arrangement, the first loudspeaker is arranged at a first distance from a first active noise control target position, wherein the first active noise control target position is a position at which noise is to be suppressed, and wherein the first distance is a length of the shortest path between the first loudspeaker and the first active noise control target position through free air. The first microphone is arranged at a second distance from the first loudspeaker that equals the first distance, and the position of the first microphone differs from the first active noise target position.

A method for binaural synthesis of at least one virtual sound source comprises operating a first device comprising at least four physical sound sources, wherein, when the first device is used by a user, at least two physical sound sources are positioned closer to a first ear of the user than to a second ear, and at least two physical sound sources are positioned closer to the second ear than to the first ear, and wherein, for each ear, at least two physical sound sources are configured to acoustically induce natural directional pinna cues associated with different directions of sound arrival at the ear of the user. The method further comprises receiving and processing at least one audio input signal and distributing at least one processed version of the audio input signal at least between 4 kHz and 12 kHz over at least two physical sound sources for each ear.

A headset arrangement for virtual reality, augmented reality or mixed reality applications is configured to induce natural directional pinna cues. The arrangement comprises a support structure configured to be arranged on a user's head and to hold a display in front of the user's eyes. For each ear, the support structure comprises at least a first sound source and a second sound source, wherein, when the support structure is arranged on a user's head, the first sound source and the second sound source are arranged such that at the concha of the user a primary sound incidence direction of sound emitted by the first sound source is essentially opposing to a primary sound incidence direction of sound emitted by the second sound source. The primary sound incidence direction is the direction from which the sound emitted by a sound source reaches the concha for the first time.

A headphone arrangement is configured to induce natural directional pinna cues. The arrangement comprises an ear cup comprising a frame configured to at least partly encircle the ear of a user, wherein the frame is at least partially hollow. The arrangement further comprises a loudspeaker arranged within a wall of a frontal part, a rear part, an upper part, and/or a lower part of the frame, the loudspeaker comprising a membrane, a first side of the membrane facing a cavity inside the frame, and a second side of the membrane facing the outside. At least one loudspeaker is arranged at a first angle with respect to a median plane crossing a user's head midway between the user's ears such that a main direction of sound propagation is directed away from the median plane, and the second side of the membrane is directed away from the median plane.