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 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 audio system comprises an array of transparent piezoelectric transducers on a transparent surface. Each transparent piezoelectric transducer includes one or more piezoelectric layers and one or more conductive layers that are substantially transparent to visible light. A transparent piezoelectric transducer may include, e.g., a first conductive layer, a first piezoelectric layer on the first conductive layer, and a second conductive layer on the first piezoelectric layer. Or in another example, the transparent piezoelectric transducer includes many (e.g., 20-30) piezoelectric layers and many (e.g., 20-30) conductive layers.

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 loudspeaker includes a first electro-acoustic transducer, a horn acoustically coupled to the first electro-acoustic transducer, and a first acoustic leak that is acoustically coupled to the horn. The first acoustic leak is positioned so as to reduce a peak in a frequency response of the loudspeaker at the targeted frequency without removing the targeted frequency from the output of the loudspeaker.

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.

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 wearable speaker includes a pair of speaker boxes that are attached on both ends of an attached band and a speaker unit and a passive radiator that are attached on each of the speaker boxes. The attached band is a neck hanging unit that is attachable on a neck of a user of the wearable speaker.

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.