According to one embodiment, an estimating apparatus includes an insertion tube, a first sensor, a second sensor, a processing unit, an adder, and an analyzer. The insertion tube is detachably mounted midway along a coupling tube that couples an excitation source to a main unit. The first sensor is provided inside the insertion tube at a first distance from an exit of a space housing the excitation source. The second sensor is provided at a second distance from the first sensor. The processing unit performs filter processing to a first signal obtained by the first sensor. The adder adds a filtered signal and a second signal obtained by the second sensor, the first signal being the first signal having undergone filter processing by the processing unit. The analyzer analyzes a frequency of a signal obtained by the adder.

A wireless earpiece includes a wireless earpiece housing, a processor disposed within the wireless earpiece housing, at least one microphone operatively connected to the processor, and at least one speaker operatively connected to the processor. The processor is configured to receive audio from the at least one microphone, perform processing of the audio to provide processed audio, and output the processed audio to the at least one speaker. The processing of the audio involves identifying body generated sounds generated by a body of a user of the wireless earpiece and removing the body generated sounds.

A wireless earpiece includes a wireless earpiece housing, a processor disposed within the wireless earpiece housing, at least one microphone operatively connected to the processor, and at least one speaker operatively connected to the processor. The processor is configured to receive audio from the at least one microphone, perform processing of the audio to provide processed audio, and output the processed audio to the at least one speaker. The processing of the audio involves identifying body generated sounds generated by a body of a user of the wireless earpiece and removing the body generated sounds.

Adaptive filters output a cancellation sound from a speaker, a selector selects outputs of a plurality of auxiliary filters each corresponding to different positions, a subtractor subtracts the selected output from the output of the microphone and outputs the subtracted output to the adaptive filter as an error signal, and a position detection device detects a position of a head of a user. A transfer function estimated so that the error signal becomes 0 when noise is canceled at the corresponding position is preset in the auxiliary filter. When the auxiliary filter corresponding to the position close to the head of the user changes, the switching control unit stepwise increases the frequency with which the output of the auxiliary filter is selected by the selector to 100%.

According to one embodiment, an estimating apparatus includes an insertion tube, a first sensor, a second sensor, a processing unit, an adder, and an analyzer. The insertion tube is detachably mounted midway along a coupling tube that couples an excitation source to a main unit. The first sensor is provided inside the insertion tube at a first distance from an exit of a space housing the excitation source. The second sensor is provided at a second distance from the first sensor. The processing unit performs filter processing to a first signal obtained by the first sensor. The adder adds a filtered signal and a second signal obtained by the second sensor, the first signal being the first signal having undergone filter processing by the processing unit. The analyzer analyzes a frequency of a signal obtained by the adder.

Embodiments are disclosed relating to an active noise reducing system and method for a headphone with a rigid cup-like shell which has an outer surface and an inner surface that encompasses a cavity with an opening. The system and method include picking up sound at least at three positions that are regularly distributed over the outer surface, and providing a first electrical signal that represents the picked-up sound. The system and method further include: filtering the first electrical signal to provide a second electrical signal, and generating in the opening of the cavity sound from the second electrical signal. Filtering is performed with a transfer characteristic that is configured so that noise that travels through the shell from beyond the outer surface to beyond the inner surface is reduced by the sound generated in the opening.

An in-ear active noise reduction earphone includes a housing, and the housing includes a rear chamber and a front chamber, and the housing is laterally provided with a sound generating unit separating the rear chamber from the front chamber; the rear chamber is located at a top of the housing, a feedforward microphone is installed inside the rear chamber, the front chamber is located at a bottom of the housing, and a feedback microphone is installed inside the front chamber; and the front chamber includes a first front chamber and a second front chamber, and the feedback microphone is installed inside the second front chamber.

According to an example embodiment, an apparatus for active cancellation of sound and vibration is provided, the apparatus including sound and vibration generation components for jointly producing vibration and sound under control of a driving signal provided as input thereto, the components being arranged inside a padding to generate mechanical vibration that is perceivable as a vibration and sound on at least one outer surface of the padding and to radiate a sound through the at least one outer surface of the padding, a feedback unit for providing feedback information that is indicative of acoustic energy of sound and vibration inside the padding, and a drivert for generating the driving signal in dependence of the feedback information so as to reduce energy of ambient sound and vibration induced inside the padding due to one or more external sources of sound and vibration.

An active duct noise control system and a method thereof are provided, including a duct, a noise source speaker, a microphone, a plurality of noise-cancelling speakers, and a plurality of controllers. Wherein, the noise source speaker generates the primary noise, and the microphone is disposed to receive the residual noise. The plurality of noise-cancelling speakers are disposed between the noise source speaker and the microphone and respectively generate noise-cancelling audio frequencies to offset the primary noise and reduce the residual noise. The plurality of controllers are respectively connected to the plurality of noise-cancelling speakers and the noise source speaker and calculate each of the noise-cancelling audio frequencies generated by each of the plurality of noise-cancelling speakers according to the multi-channel inverse filtering principle.

In a signal processing device, a signal processing method, a recording medium, and a rangehood apparatus, a filter coefficient is set in a sound cancelling filter, and the sound cancelling filter outputs a cancellation signal. A coefficient calculator calculates a first filter coefficient. An oscillation suppressor calculates a second filter coefficient by applying a window function to the first filter coefficient to set the second filter coefficient as the filter coefficient.