An axial fan that includes a casing having an inner space that penetrates in one direction, and a rotor blade disposed in the inner space of the casing, and a silencer that is disposed at a position connected to the inner space of the axial fan are provided, in which the axial fan has a sound pressure distribution having a position at which a sound pressure is high and a position at which the sound pressure is low in a circumferential direction in the inner space during driving, and the silencer is disposed at the position of the axial fan in the circumferential direction at which the sound pressure is high and is not disposed at the position at which the sound pressure is low.

A muffler for an exhaust system of an internal combustion engine includes a muffler housing having a peripheral wall elongated along a longitudinal axis of the muffler housing. The peripheral wall has first and second end walls. A muffler insert is surrounded by the peripheral wall and is supported thereon. The muffler insert has a retaining wall extending in a direction of the longitudinal axis. The peripheral wall has a peripheral wall opening and a first exhaust-gas routing pipe has a first end region and is positioned with the first end region thereof engaging in the peripheral wall opening. The first exhaust-gas routing pipe has a second end region and is secured by the second end region thereof to the retaining wall. The first exhaust-gas routing pipe is of multi-part configuration and has a first pipe part and a second pipe part.

An acoustic core may include an array of resonant cells configured as a plurality of resonant cell groups. The resonant cell groups may include a plurality of resonant cells configured as a partitioned resonant cell that include a converging resonant cell and a diverging resonant cell. The converging resonant cell and the diverging resonant cell may be defined by a plurality of cell walls integrally formed with one another and a partition integrally formed with the plurality of cell walls. The partition may at least partially delimit the converging resonant cell from the diverging resonant cell. The converging resonant cell may define an upper resonant space delimited by the partition and a top face of the array of resonant cells. The diverging resonant cell may define a lower resonant space delimited by the partition and a bottom face of the array of resonant cells.

An audio system for a seat headrest includes N speaker(s), each configured to be integrated into a seat headrest, N being an integer greater than or equal to 1, and an audio processing device including an electronic transmission channel connected to the speaker(s) and configured to transmit at least one audio stream via the speaker(s). The audio system comprises P microphone(s), each configured to be integrated into the headrest, P being an integer greater than or equal to 1. The audio processing device further includes an electronic receiving channel connected to the microphone(s) and configured to receive at least one sound signal via the P microphone(s).

An audio system for a seat headrest includes N speaker(s), each configured to be integrated into a seat headrest, N being an integer greater than or equal to 1, and an audio processing device including an electronic transmission channel connected to the speaker(s) and configured to transmit at least one audio stream via the speaker(s). The audio system comprises P microphone(s), each configured to be integrated into the headrest, P being an integer greater than or equal to 1. The audio processing device further includes an electronic receiving channel connected to the microphone(s) and configured to receive at least one sound signal via the P microphone(s).

A sound attenuator has an inner pipe (12) with expansion sections (121) of enlarged diameter corresponding to the constriction sections (141) of an outer pipe (14). The expansion sections (121) in pairs axially delimit an intermediate inner pipe section (122) containing a wall opening (18) and having a reduced diameter relative to the expansion sections (121). The inner surface of the outer pipe (14) in each of its constriction sections (141) is connected to the outer surface of the inner pipe (12) in its respective corresponding expansion section (121). A method of manufacturing such a sound attenuator (10) also is provided and uses internal high-pressure forming.

A sound reducer (10) has a housing (14) with a housing wall bounding an interior space (141). The housing wall has a mantle (142) extending longitudinally along a housing axis. Two end walls (143) are transverse to the housing axis. A main tube (12) extends through the interior space (141) and has a first and second ends (121). Windows (22) are formed as tube wall openings within the interior space (141). The first end (121) of the main tube (12) is fixed at a first passage (18a) through the housing wall, and the second end (122) of the main tube (12) is fixed at a second passage (18b) through the housing wall. At least the second passage (18b) passes eccentrically through one of the end walls (143). The main tube (12) is curved in a main plane and the first passage (18a) passes through the mantle (142).

An example device includes an imaging portion, an audio portion and at least one acoustic isolation feature. The audio portion is integrally coupled to the imaging portion. The audio portion is to provide an audio output. The at least one acoustic isolation feature is to facilitate acoustic separation of the imaging portion and the audio portion.

An example device includes an imaging portion, an audio portion and at least one acoustic isolation feature. The audio portion is integrally coupled to the imaging portion. The audio portion is to provide an audio output. The at least one acoustic isolation feature is to facilitate acoustic separation of the imaging portion and the audio portion.

A backing member includes: a resin body including a lower surface and an upper surface opposite to each other; a plurality of leads each of which extends in a first direction from the lower surface toward the upper surface, and that are embedded at pitches in the resin body; and a plurality of insulating spacers each of which is provided between adjacent ones of the leads and extends in a second direction intersecting with the first direction, and that contact the leads.