Yamaha Corporation

Rento Tanase

Atsushi Yoshida

Keiichi Fukatsu

Yasutaka Nakamura

Tetsu Kobayashi

Masaru Matsushita

Yoshikazu Honji

Kunio Hiyama

Satoshi Sekine

Takashi Kato

Shinichi Kato

Fusako Ishimura

A standing wave attenuation device is installed in a cabin of a vehicle so as to reduce a standing wave caused by external noise such as road noise. The standing wave attenuation device provides a closed loop including a feedback comb filter with a feedback loop, a microphone, a speaker, and a delay element. The delay element adjusts the phase of the output signal of the feedback comb filter such that the time needed for one-time circulation of a signal through the feedback loop matches a half period of the standing wave. An original sound including the standing wave is picked up by the microphone and subjected to processing so that the speaker produces a sound wave with the inverse phase against the phase of a sound wave constituting the standing wave, so that the standing wave is canceled out by the sound wave emitted from the speaker.

Standing wave attenuation device

An electronic keyboard musical instrument, including: a keyboard; a musical-sound signal generating circuit; at least one speaker for emitting sound in accordance with a generated signal; a speaker accommodating body accommodating the speaker in its inner space; and at least one resonator disposed in the accommodating body, wherein the accommodating body includes a sound emission path by which the sound emitted by the speaker is introduced to an exterior of the accommodating body via the inner space for sound propagation to the exterior, a control point of the resonator is located at a position corresponding to an antinode of a sound pressure in a natural vibration mode at a specific frequency generated in the inner space by driving of the speaker, and the resonator resonates at the specific frequency for adjusting the sound pressure, whereby the sound is emitted from the sound emission path to the exterior.

Sound adjusting system and electronic musical instrument

An acoustic resonator adaptable to a sound chamber is designed to decrease a sound pressure while increasing a particle velocity of medium particles in a low frequency range without increasing the overall size thereof. The acoustic resonator is constituted of a pipe member having one opening end and a resistance member embracing a high resistance region and a low resistance region. The resistance member is inserted into the pipe member such that one end thereof matches the opening end of the pipe member while the other end thereof is disposed at a predetermined position inside a hollow cavity of the pipe member. The high resistance region embraces an antinode region of the particle velocity distribution with respect to a standing wave occurred in the hollow cavity at a resonance frequency, thus causing an acoustic phenomenon decreasing the resonance frequency compared to a single unit of the pipe member.

Acoustic resonator and sound chamber

A sound absorber is formed by covering the opening of a housing with a vibration member having a flat shape or a film shape so as to define an air layer therebetween. The sound absorber is attached to the wall of a room such that the vibration member is positioned opposite to the wall with a prescribed space therebetween. Sound generated in the room particularly in low frequencies enters into the space between the vibration member and the wall so as to cause vibration of the vibration member due to the pressure difference between the sound pressure applied to the space and the internal pressure of the air layer, thus consuming energy of sound waves. Thus, it is possible to efficiently absorb low-frequency sound with a reduced thickness of the air layer.

Sound absorbing structure and sound chamber

A sound absorbing structure is constituted of a vibration plate and a rear air layer and is installed in a luggage compartment or trunk which is separated from a cabin in a vehicle. Sound waves entering into the luggage compartment drive the vibration plate to vibrate so that acoustic energy is converted into mechanical energy and is consumed by way of vibration of the vibration plate. By appropriately setting parameters and dimensions, the sound absorbing structure efficiently absorbs low-frequency sound such as road noise occurring due to friction of wheels of the vehicle traveling on a road.

Sound absorbing structure built into luggage compartment of vehicle

A sound absorbing structure is constituted of a housing having a hollow portion and an opening and a vibration member composed of a board or diaphragm. The vibration member is a square-shaped material having elasticity composed of a synthetic resin and is bonded to the opening of the housing, thus forming an air layer closed inside the sound absorbing structure by the housing and the vibration member. In the sound absorbing structure, when the lateral/longitudinal dimensions of the air layer and characteristics of the vibration member (e.g. a Young's modulus, thickness, and Poisson's ratio) are set such that the fundamental frequency of a vibration occurring in a bending system falls within 5% and 65% of the resonance frequency of a spring-mass system, a vibration mode having a large amplitude occurs in a frequency band lower than the resonance frequency of the spring-mass system, this improving the sound absorption coefficient.

Sound absorbing structure and vehicle component having sound absorbing property

A product purchase support apparatus which is capable of providing detailed information on a product in accordance with a preference and the like of each customer. Attribute information indicative of attributes of customers and including priority evaluation information indicative of priority evaluation items therein is stored. Detailed information on each of the products is also stored. The attribute information associated with a customer ID for identifying a customer and detailed information on a product associated with the bar code information for identifying product detailed information are identified. Information related to the priority evaluation information included in the identified attribute information is only extracted and processed using the priority evaluation information as retrieval keys from the identified detailed information on the product. The customer ID and the bar code information associated with the processed information are stored in association with each other and transmitted as product inquiry information.

Product purchase support apparatus, product purchase support method, product purchase support program, information creating apparatus, information creating method, information creating program, and privilege granting system

In an energy-saving evaluation apparatus for evaluating energy conservation for a machine that is to be operated by a user, the energy-saving evaluation apparatus includes: a detection unit that includes a monitor device for measuring a running state of the machine, detects an operating state of the machine operated by the user through measuring the running state of the machine by the monitor device; and an evaluation unit that performs an energy-saving evaluation based on the detected operating state of the machine.

Energy-saving evaluation apparatus, ecological driving evaluation apparatus, energy saving evaluation system, ecological driving evaluation system and method thereof

In the floor base panel (), an area on the support board () of the vibration proof support leg () is formed solid, and in the other area, a plurality of cavities () extending parallel to the floor surface are formed. Thereby, because the vibration energy propagated from the impact point of the floor base panel () is reflected on the boundary between the cavity formation area and the solid area, and repeatedly passes the cavity formation area, it is attenuated in a short time, and the vibration energy or sound energy transmitted to a slab () can be reduced.

Floor structure and floor base panel

Speaker includes a diaphragm, and a linear vibrating device attached to a peripheral portion of the diaphragm. The linear vibrating device includes a conductor line meandering in a wave-like shape along the surface of the diaphragm, and magnets disposed in opposed relation to the conductor line. The magnets are disposed in regions surrounded by adjoining mountain portions and adjoining valley portions of the conductor line. The magnets are arranged in such a manner that every adjoining magnets have their magnetic poles of opposite polarities located close to the conductor line.

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Iwata, Japan

Rento Tanase