Abstract: An acoustic device includes an enclosure and a bass reflex port that includes a tube body. An inner wall surface of the tube body includes multiple regions in which viscous resistances in a tube axis direction of moving air and the inner wall surface are different. The multiple regions are provided along a circumferential direction of the inner wall surface. The tube body is attached to an opening area in the enclosure.

Abstract: A bass reflex port including: a tubular body portion; and a surface forming portion which is board-like, and continuous to an inner wall of the tubular body portion and which has a surface extending radially outwardly from an opening end of the tubular body portion disposed in a housing of a speaker, wherein the surface forming portion extends linearly in a direction away from a tube axis of the tubular body portion in a cross section parallel to the tube axis.

Abstract: A bass reflex port including: a tubular body portion; and a surface forming portion which is board-like, and continuous to an inner wall of the tubular body portion and which has a surface extending radially outwardly from an opening end of the tubular body portion disposed in a housing of a speaker, wherein the surface forming portion extends linearly in a direction away from a tube axis of the tubular body portion in a cross section parallel to the tube axis.

Abstract: An acoustic device includes an enclosure and a bass reflex port that includes a tube body. An inner wall surface of the tube body includes multiple regions in which viscous resistances in a tube axis direction of moving air and the inner wall surface are different. The multiple regions are provided along a circumferential direction of the inner wall surface. The tube body is attached to an opening area in the enclosure.

Abstract: An acoustic structure defining a cavity in which a sound wave propagates, wherein a first portion of the cavity substantially corresponding to a position of a node or an antinode of a standing wave generated in the cavity has an area different from an area of a second portion of the cavity except the first portion, the area being on a plane orthogonal to a direction of propagation of the sound wave.

Abstract: An acoustic structure defining a cavity in which a sound wave propagates, wherein a first portion of the cavity substantially corresponding to a position of a node or an antinode of a standing wave generated in the cavity has an area different from an area of a second portion of the cavity except the first portion, the area being on a plane orthogonal to a direction of propagation of the sound wave.

Abstract: A vehicle sound generation apparatus 20 is constituted by a first pressure sensor 21a, a second pressure sensor 21b, a signal processing section 24 which performs processing of changing pressure signals output from the first pressure sensor 21a and the second pressure sensor 21b in accordance with the operation state of an automobile 10, and speakers 28a, 28b which output, as an intake sound of an engine 12, a sound pressure signal processed by the signal processing section 24. The first pressure sensor 21a is provided on an intake duct 15 connecting an air cleaner 16 and a throttle body 17 at a position between the air cleaner 16 and the center of the intake duct 15, and the second pressure sensor 21b is provided between the engine 12 and the throttle body 17.

Abstract: An acoustic apparatus includes a vibration part configured to generate an acoustic vibration, a tube having a cavity that faces the vibration part, and at least one open tube connected to the tube via a first open end and a second open end. A length of the at least one open tube is an integer-fold of substantially a half of a wavelength of a standing wave produced in the tube. The first open end is positioned substantially at an anti-node of the standing wave produced in the tube.

Abstract: A microphone device includes: a housing having an opening section in an upper face thereof; and a non-directional microphone unit incorporated in the housing and provided inside the opening section. The upper face of the housing has a shape in which a distance from an edge defined as a boundary between the upper face and a side face or a bottom face to the opening section throughout a whole circumference of the upper face changes in ½ or more of the whole circumference of the edge and an average value of the distance from the edge to the opening section is shorter than ½ of a wavelength of a sound wave in a frequency range in which an auditory sensitivity of humans is low.

Abstract: Provided is a sound generating device (20) for a vehicle, including: a plurality of pressure sensors (21a to 21d) for detecting air pressures of an air intake sound of an engine (12) and outputting the air pressures as sound pressure signals; a signal processing unit (24) for performing processing of changing the sound pressure signals in accordance with a driving condition of a vehicle (10); and loudspeakers (28a and 28b) for outputting the sound pressure signals as the air intake sound of the engine (12). Then, the plurality of pressure sensors (21a to 21d) are provided at an interval in a circumferential direction of an outer periphery of an air intake duct (15) at positions in a vicinity of an air flow meter (18) on an air cleaner (16) side with respect to a center of the air intake duct (15), the air intake duct (15) connecting the air cleaner (16) to a throttle body (17).

Abstract: A keyboard instrument includes: an instrument body; at least one speaker; and at least one acoustic pipe configured to collect a sound emitted from the at least one speaker and guide the sound to at least one sound emitting opening formed in a front face of the instrument body.

Abstract: A tubular body having an air flow passage, wherein an area of a cross section, in a direction perpendicular to a tube axis, of a space enclosed with an inner wall of the tubular body increases toward an open end thereof, wherein a curvature of the inner wall at an end portion of the tubular body near the open end is repeatedly increased and decreased along a circumferential direction of the inner wall, and wherein, when the inner wall in a cross section of the end portion in the direction perpendicular to the tube axis is viewed from the tube axis, a convex portion at which the inner wall protrudes in a direction away from the tube axis and a concave portion at which the inner wall is recessed in a direction toward the tube axis are repeatedly formed along the circumferential direction.

Abstract: A bass reflex port having a tubular shape for air flows, wherein an angle of a first inner radial line with respect to a reference plane including a center axis of the bass reflex port differs from an angle of a second inner radial line with respect to the reference plane, the first line being orthogonal to the center axis and passing a first characteristic point on an inner circumference of the bass reflex port in a first transverse cross section perpendicular to the center axis, the second line being orthogonal to the center axis and passing a second characteristic point corresponding to the first characteristic point and located on the inner circumference in a second transverse cross section perpendicular to the center axis, the first transverse cross section and the second transverse cross section differing form each other in position in a direction of extension of the center axis.

Abstract: An audio device is provided with a plurality of Helmholtz resonators. Whereas a cross-sectional area of a neck and a volume of a cavity communicating with the neck are same between at least two of the Helmholtz resonators, a ratio of minimum and maximum values of distances between a center of gravity of the cross section of the neck and individual points defining an outer periphery of the cross section is different between said at least two of the Helmholtz resonators.

Abstract: A microphone device includes: a housing having an opening section in an upper face thereof; and a non-directional microphone unit incorporated in the housing and provided inside the opening section. The upper face of the housing has a shape in which a distance from an edge defined as a boundary between the upper face and a side face or a bottom face to the opening section throughout a whole circumference of the upper face changes in ½ or more of the whole circumference of the edge and an average value of the distance from the edge to the opening section is shorter than ½ of a wavelength of a sound wave in a frequency range in which an auditory sensitivity of humans is low.