A playback device comprises an electroacoustic transducer; an acoustic waveguide in fluid communication with the transducer; and a housing delimiting an opening of the waveguide, the opening extending around an axis passing through the transducer. The opening may have a radial distance from the axis that varies with an azimuthal angle about the axis. An acoustic path length within the waveguide, between the transducer and the opening, is substantially constant and independent of azimuthal angle about the axis.

A playback device comprises an electroacoustic transducer; an acoustic waveguide in fluid communication with the transducer; and a housing delimiting an opening of the waveguide, the opening extending around an axis passing through the transducer. The opening may have a radial distance from the axis that varies with an azimuthal angle about the axis. An acoustic path length within the waveguide, between the transducer and the opening, is substantially constant and independent of azimuthal angle about the axis.

An acoustic transducer comprises a transducer substrate, and an aperture having a non-circular perimetral shape defined through the transducer substrate. A diaphragm is disposed on the transducer substrate and coupled to a surface of the transducer substrate via at least one diaphragm anchor such that a gap is defined between the diaphragm and the transducer substrate, and an outer periphery of the diaphragm extends radially outwards of a rim of the aperture such that a portion of the diaphragm overhangs the aperture.

An acoustic transducer comprises a transducer substrate, and an aperture having a non-circular perimetral shape defined through the transducer substrate. A diaphragm is disposed on the transducer substrate and coupled to a surface of the transducer substrate via at least one diaphragm anchor such that a gap is defined between the diaphragm and the transducer substrate, and an outer periphery of the diaphragm extends radially outwards of a rim of the aperture such that a portion of the diaphragm overhangs the aperture.

A loudspeaker comprising: an acoustic diaphragm having front and rear surfaces, the acoustic diaphragm in use being driven so as to vibrate and radiate acoustic waves from its front surface in a forward direction away from the loudspeaker and from its rear surface in a rearward direction, and a drive unit located rearwardly or to the front/outside of the diaphragm, there being at least one open duct leading in a rearward direction away from the diaphragm, in which the at least one open duct has a cross-sectional area which decreases in the rearward direction, and in which acoustic waves radiated from the rear surface of the diaphragm pass through the open duct before contacting a front surface of an acoustic metamaterial absorber located generally behind the drive unit and immediately to the rear of the duct.

An omnidirectional sound source is formed by mounting a loudspeaker in an enclosed baffle, preferably formed as a low profile hemi-spherical, convex cap with a small circular orifice at its apex and a planar base. The loudspeaker is mounted within the baffle, affixed to the underside of the baffle cap directly beneath the orifice. Substantially plane audio-frequency wavefronts emanating from the immediate vicinity of the loudspeaker diaphragm pass through the orifice and, by the process of diffraction emerge as spherical waves. The spherical wavefronts follow the smooth, axisymmetric, gently curved contour of the low-profile, hemispherical baffle and are not distorted by edge effects where the baffle joins its planar base. As a result, an omnidirectional sound source is obtained.

An electronic apparatus includes a housing having a sound receiving hole that guides a sound outside the housing into the housing, a substrate that is disposed in the housing and on which a microphone is mounted, an elastic member that is disposed so as to fill a gap between the substrate and an inner wall of the housing excluding a portion of the inner wall that is located around the sound receiving hole and so as to form a space between the substrate and the portion of the inner wall of the housing, which is located around the sound receiving hole, and a first member that is disposed so as to partially occupy the space.

A mobile terminal is provided. The mobile terminal includes: a receiver, disposed on one side of a center line of the mobile terminal, where a sound outlet hole is provided in a display screen of the mobile terminal, a front cavity sound outlet channel of the receiver is provided inside the mobile terminal, and the front cavity sound outlet channel communicates with the sound outlet hole; and a through-hole is provided at the top of the mobile terminal, and the through-hole communicates with the front cavity sound outlet channel.

A display apparatus includes a rear cover behind a display panel, a left cover on a left side of the display panel and a right cover on a right side of the display panel and connected to the rear cover, and a left speaker adjacent to the left cover and a right speaker and the right cover where each of the left speaker and the right speaker includes a diaphragm facing the rear cover and spaced apart from the rear cover to form a slot, an enclosure surrounding a speaker driver, a sound discharge port at one end of the slot adjacent to the left cover or the right cover and through which sound reproduced by the diaphragm is discharged, and a side wall between one surface of the enclosure and the rear cover and surrounding a circumference of the diaphragm excluding the sound discharge port.

A playback device comprises an electroacoustic transducer; an acoustic waveguide in fluid communication with the transducer; and a housing delimiting an opening of the waveguide, the opening extending around an axis passing through the transducer. The opening may have a radial distance from the axis that varies with an azimuthal angle about the axis. An acoustic path length within the waveguide, between the transducer and the opening, is substantially constant and independent of azimuthal angle about the axis.