A loudspeaker device includes at least one loudspeaker, a loudspeaker holder holding the at least one loudspeaker in a reference range away from the ear of a user by a reference distance, a first microphone collecting an environmental sound and outputting an electrical signal, a second microphone attached to a position where a sound output from the at least one loudspeaker is collected, the second microphone collecting a synthetic sound synthesized from the sound output from the at least one loudspeaker and the environmental sound and outputting an electrical signal, and a processor controlling the at least one loudspeaker so as to output a sound for reducing the environmental sound based on the electrical signals representing the sounds collected by the first microphone and the second microphone.

An active sound barrier has at least one passive sound absorber at or near a boundary location. A microphone provides an output to a frequency division module, in which a plural of frequencies are filtered to provide outputs corresponding to frequency segments of the receiving transducer output at respective ones of the frequencies. An active driving circuit drives plural speakers or output transducers at respective ones of the frequencies, with at least a subset of the speakers or output transducers at or close to the barrier. The speakers or output transducers cooperate with the passive sound absorber to reduce noise across a wide frequency band as well as to effect an electrically switchable soft boundary.

An audio device for receiving radio communication. The audio device is configured to receive radio communication as a received radio signal. The audio device includes a hear-through element configured to provide a hear-through signal to a user in response to a received ambient sound signal, and an adaptive auto-gain element configured to perform an auto-gain function of the received radio signal according to an adaptive gain value resulting in a modified radio signal, and to set the adaptive target level for the auto-gain function in response to the hear-through signal.

Disclosed herein is a system for facilitating stress adaption in a workstation. Accordingly, the system may include microphones disposed on the workstation. Further, the one or more microphones may be configured for generating first sound signals of first sounds associated with an environment of the workstation. Further, the system may include a processing device communicatively coupled with the microphones. Further, the processing device may be configured for analyzing the first sound signals, determining first sound characteristics of the first sounds, determining second sound characteristics of second sounds, and generating second sound signals for the one or more second sounds. Further, the system may include acoustic devices disposed on the workstation. Further, the acoustic devices may be communicatively coupled with the processing device. Further, the acoustic devices may be configured for emitting the second sounds based on the second sound signals. Further, the second sounds destructively interfere with the first sounds.

A sound muffling chamber covers a nose and mouth in an airtight manner. The sound muffling chamber includes a microphone that detects vocal sound waves in the sound muffling chamber and generates a voice signal. A digital signal processing system analyzes the voice signal and generates a voice cancellation signal. A sound silencing chamber includes a speaker that generates out of phase sound waves in response to the voice cancellation signal that superimposes on and cancels the vocal sound waves. A sound decelerator is positioned between the sound muffling chamber and the sound silencing chamber and configured to increase a traveling time of the vocal sound waves such that the vocal sound waves' arrival at the sound silencing chamber may be synchronized with the arrival of a voice cancellation signal. The sound muffling chamber may include inflatable cells separated by slats such that the sound muffling chamber is foldable.

An earphone includes an earphone assembly and first and second electro-acoustic transducers. The earphone assembly includes an earphone body with an inner surface, an acoustic opening and a cavity defined inside the body by the inner surface and the acoustic opening. The earphone body further includes an acoustic impedance branch, such as a waveguide, that reduces a magnitude of a resonance at a first resonance frequency for an occluded ear canal defined by the cavity of the earphone assembly and an ear canal of a user when the earphone is at least partially inserted into the ear canal. The first electro-acoustic transducer is disposed at the inner surface of the earphone body and is configured to generate a first acoustic signal. The second electro-acoustic transducer is disposed along a length of the acoustic impedance branch and is configured to generate a second acoustic signal.

A structural damper (2) having an acoustic black hole (5), at least one sensor (7), a damper structure (4), an actuator (8) configured to apply an actuating force to the damper structure (4) and a controller (H) configured to control the actuator in dependence on a signal from the at least one sensor so as to provide structural damping of a primary structure (3).

An apparatus is provided. The apparatus includes a plurality of flow guiding structures spatially aligned in a first row, each of the plurality of flow guiding structures comprising a fin-shape to funnel airflow at a trailing edge of each of the plurality of flow guiding structures. The apparatus also includes a plurality of flow separating structures spatially aligned in a second row interleaved between each of the plurality of flow guiding structures, each of the plurality of flow separating structures comprising a fin-shape configured to split airflow received from the plurality of flow guiding structures.

An audio enhanced hearing protection system to be worn by a user includes an ambient noise reduction assembly having a primary noise reduction unit and a secondary noise reduction unit. The audio enhanced hearing protection system also includes an audio input assembly having one or more environmental microphones to receive raw environmental audio signals. The raw audio signals are transformed into processed audio signals via a digital signal processing assembly prior to transmission to a user. The audio enhanced hearing protection system also includes an audio output assembly having at least one speaker to transmit processed audio signals to a user.

Disclosed is an active-noise control device including two passive attenuation earphones each provided with an external microphone, an internal microphone and a loudspeaker. The control device includes a first processing chain having a feedforward filter, a feedback filter and a reconstruction module. The control device includes a second processing chain having a sound source identification module, said second processing chain being implemented in parallel with the first processing chain, and being suitable for parameterizing the first processing chain.