A loudspeaker includes a diaphragm, a frame, an attachment unit, and a fixing member. The frame has a front surface, a mounting surface disposed on a side opposite to the front surface, and a wall surface disposed in a standing manner from the mounting surface. And the frame holds an outer peripheral edge of the diaphragm. The attachment unit includes: a base portion having a top surface facing the mounting surface, a bottom surface on a side opposite to the top surface, a first side surface facing the wall surface, and a second side surface disposed on a side opposite to the first side surface; a first base rib projecting toward the wall surface from the first side surface; a second base rib projecting from the second side surface and extending to the top surface; and a locking portion disposed on a side near the bottom surface of the base portion. The fixing member penetrates the frame from the front surface to the mounting surface and is fixed to the base portion by screwing.

Low frequency alarm tones emitted by life safety devices are more like to notify sleeping children and the elderly. Disclosed herein is a life safety device equipped with a novel, compact, quarter-wave, folded resonant cavity which significantly increases the low frequency (400-700 Hz square wave) acoustic efficiency of an audio output transducer when the folded resonant cavity is acoustically coupled to the transducer forming an audio output apparatus. The folded resonant cavity is comprised of undulating, annular, acoustic passages to significantly reduce the length of the resonant cavity, thereby permitting the audio output apparatus to fit within the housing of conventional size life safety devices such as, but not limited to, residential and commercial smoke alarms and carbon monoxide alarms. Battery powered embodiments of the audio output apparatus comprising a folded resonant cavity passed audibility tests for low frequency alarm tones in smoke alarms specified by UL217.

A speaker system is disclosed for providing customised acoustical wavefronts with vertical and horizontal pattern control and amplitude and phase control. The system including a speaker housing (1) having therein at least a first array (2) of high frequency driver segments (3) and at least a secondary array (4) of low frequency driver segments (5) disposed behind said first array (2), said first array having sufficient space between said driver segments (3) to allow acoustic transparency whereby a wavefront from said secondary array (4) can substantially pass through said first array (2).

A speaker system is disclosed for providing customised acoustical wavefronts with vertical and horizontal pattern control and amplitude and phase control. The system including a speaker housing (1) having therein at least a first array (2) of high frequency driver segments (3) and at least a secondary array (4) of low frequency driver segments (5) disposed behind said first array (2), said first array having sufficient space between said driver segments (3) to allow acoustic transparency whereby a wavefront from said secondary array (4) can substantially pass through said first array (2).

To reduce the driving loss in the diaphragm, and to ensure a good sound output in the wide bandwidth. It includes a circular coil bobbin at least partly disposed between a yoke and a magnet, a coil wound around the coil bobbin, the coil being configured to be moved with the coil bobbin where a driving current is supplied to the coil, a piezoelectric element having one end coupled to one end of the coil bobbin in a movement direction, the piezoelectric element being configured to be expanded and contracted and moved in a direction same as the movement direction where an electric current is supplied to the piezoelectric element, and a diaphragm having an inner circumference part coupled to another end of the piezoelectric element, and a coupled part of the diaphragm to the piezoelectric element and a coupled part of the piezoelectric element to the coil bobbin are positioned on a straight line in the movement direction.

To reduce the driving loss in the diaphragm, and to ensure a good sound output in the wide bandwidth. It includes a circular coil bobbin at least partly disposed between a yoke and a magnet, a coil wound around the coil bobbin, the coil being configured to be moved with the coil bobbin where a driving current is supplied to the coil, a piezoelectric element having one end coupled to one end of the coil bobbin in a movement direction, the piezoelectric element being configured to be expanded and contracted and moved in a direction same as the movement direction where an electric current is supplied to the piezoelectric element, and a diaphragm having an inner circumference part coupled to another end of the piezoelectric element, and a coupled part of the diaphragm to the piezoelectric element and a coupled part of the piezoelectric element to the coil bobbin are positioned on a straight line in the movement direction.

A sound generating device, comprising a shell structure having a gap between the inside and outside, wherein a first hole (22a) and a second hole (23a) opposite to each other are provided on inner shell (2a); a sound source (3) is fixed inside the first hole (22a), and a front side (31) thereof faces towards an outer shell (1a), and a back side (32) thereof faces towards the second hole (23a); a third hole (12a) opposite the first hole (22a) is provided on the outer shell (1a), and spaced apart from the sound source (3) by a distance; a backward sound wave of the sound source (3) passes through the second hole (23a) and enters into the gap, and exits from the third hole (12a) together with a forward sound wave of the sound source (3).

A sound generating device, comprising a shell structure having a gap between the inside and outside, wherein a first hole (22a) and a second hole (23a) opposite to each other are provided on inner shell (2a); a sound source (3) is fixed inside the first hole (22a), and a front side (31) thereof faces towards an outer shell (1a), and a back side (32) thereof faces towards the second hole (23a); a third hole (12a) opposite the first hole (22a) is provided on the outer shell (1a), and spaced apart from the sound source (3) by a distance; a backward sound wave of the sound source (3) passes through the second hole (23a) and enters into the gap, and exits from the third hole (12a) together with a forward sound wave of the sound source (3).

Embodiments of the present disclosure set forth a computer-implemented method comprising determining a first direction of interest associated with a user, receiving a set of audio signals associated with the first direction of interest, determining a first dominant frequency band within the set of audio signals, modifying a first portion of the set of audio signals corresponding to the first dominant frequency band, and outputting the modified set of audio signals.

An apparatus comprising: an audio transducer configured to at least one of: generate sound upon receiving an audio signal provided by the apparatus; and convert sound into an audio signal to be processed by the apparatus; a housing component comprising one or more sound apertures configured to allow the transmission of sound through the one or more sound apertures; and an acoustic cavity inside the apparatus being acoustically coupled to the audio transducer using the one or more sound apertures wherein the one or more sound apertures are configured to provide an acoustic damping.