Nippon Telegraph and Telephone Corporation

Pigeon Corporation

Ntt Corporation

Ryotaro Sato

Kazunori Kobayashi

Yoichi Nakata

Hiroyuki Uehara

Michiyo Kajinaga

Masahiro Fukui

Hitoshi Takagi

Kenta Niwa

Noriyoshi Kamado

Emi Kuramoto

There is provided an acoustic system for a user who uses a seat of an airplane, an automobile, or the like, which reproduces a sound that cannot be heard by surrounding users without using earphones or headphones. An acoustic system including a speaker system including one speaker unit that emits a sound based on an acoustic signal of a predetermined sound source, in which a sound emitted from the speaker unit is hearable in a region to be audible near the speaker unit, and by a sound emitted from the speaker unit in a back surface direction coming around to a front surface direction, the sound emitted from the speaker unit in the front surface direction and the sound emitted from the speaker unit in the back surface direction cancel each other in a region in the front surface direction far from the speaker unit.

Sound system

A reproduction apparatus that realizes reproduction of which sound leakage is small with use of a speaker installed near a head, and a method and a program thereof are provided. The reproduction apparatus is used in a seat. The reproduction apparatus includes: at least two speakers; an acquisition unit that acquires, from a predetermined sound source, an acoustic signal of which sound is emitted by the reproduction apparatus; and a control unit that controls the acoustic signal acquired by the acquisition unit such that reproduction sound is only transmitted to a first seat and the reproduction sound is not transmitted to a second seat, the speakers each emit sound of the acoustic signal controlled by the control unit, and the speakers are disposed so as to be closer to an ear of a user that sits in the first seat than to the second seat.

Reproduction apparatus, method and program for the same

There are included a first speaker processing step in which a first speakerproduces sound based on a first filtered signal, a gain multiplication step in which a gain multiplication unitgenerates a gain multiplied signal by multiplying a second filtered signal by a gain, a second speaker processing step in which a second speakerproduces sound based on the gain multiplied signal, and a gain control step in which a gain control unitcontrols the gain such that a root mean square of a collected sound signal collected by a microphoneinstalled at a mute position, which is a position at which the sound produced by the first speaker and the sound produced by the second speaker are to be muted, is relatively small.

Speaker calibration method, apparatus and program

Provided is a technique to generate a call environment that prevents call contents from being heard by a person other than a person speaking on the phone in a case where call voice is output from a speaker. Speakers installed in an automobile are denoted by SP, . . . , SP, a first filter coefficient used to generate an input signal for a speaker SPis denoted by F(ω), and a second filter coefficient that is different from the first filter coefficient and is used to generate an input signal for the speaker SPis denoted by {tilde over ( )}F(ω). A call environment generation method includes: an acoustic signal generation step of generating, when detecting a start signal of a call, a call-time acoustic signal that is obtained by adjusting volume of an acoustic signal to be reproduced during the call, by using a predetermined volume value; a first local signal generation step of generating a sound signal Sas an input signal for the speaker SPfrom a voice signal of the call by using the first filter coefficient F(ω); and a second local signal generation step of generating an acoustic signal Aas an input signal for the speaker SPfrom the call-time acoustic signal by using the second filter coefficient {tilde over ( )}F(ω).

Call environment generation method, call environment generation apparatus, and program

Provided is a filter coefficient optimization technology that makes it possible to design a stable beamformer having a good quality by considering the relationship of a filter coefficient between adjacent frequency bins. A filter coefficient optimization apparatus includes an optimization unit that calculates an optimum value of a filter coefficient w={w, . . . , w} (wis a filter coefficient of a frequency bin f) of a beamformer that emphasizes sound (target sound) from D sound source, abeing an array manifold vector in the frequency bin f corresponding to a sound wave that comes from an angular direction θin which a sound source d exists, the sound wave being a plane wave, the optimization unit calculating the optimum value based on an optimization problem of a cost function defined using a sum of a sum of a cost function L(w) and a predetermined regularization term, under a predetermined constraint condition, the predetermined regularization term being defined using a difference in phase between adjacent frequency bins relevant to a response waof the beamformer in the frequency bin f for the angular direction θ.

Filter coefficient optimization apparatus, filter coefficient optimization method, and program

The drinking cup for learning which can train babies in the drinking movement step-by-step in order to provide a baby, who is at the age of taking milk and taking the liquid food, the lessons of the technique for taking either liquids or the liquid food naturally without spilling them. The drinking cup for learning includes a main container for containing liquid, the main container having at least a cup-shaped opening and a drinking spout member removably attached to the main container. The drinking spout member includes an opening communicating with the main container and a top-opened guide means provided with barrier portions forming at least both side edges.

Growing community of inventors

Tokyo, Japan

Ryotaro Sato