Abstract: A two-way communication apparatus used for two-way speech. In the two-way communication apparatus, a plurality of microphones radially arranged in a horizontal direction are located at equal distances from a receiving and reproduction speaker. The plurality of microphones are located in pairs from the center of the receiving and reproduction speaker. Surface of a sound reflection plate facing the side surfaces of a speaker housing are curved to a flared shape and diffuse the sound output from an upper sound output opening in all orientations in the horizontal direction by cooperating with the sound reflection surface. A DSP receives as input sound pickup signals of one pair of the microphones, selects the microphone for which the highest sound is detected, and transmits the sound pickup signal to the two-way communication apparatus of the other party via a telephone line.

Abstract: A communication apparatus used for two-way speech wherein the acoustic couplings between a speaker and microphones can be made equal by a simple method, wherein radially arranged microphones are located at equal distances from a speaker, a test signal generation unit outputs a pink noise signal to the speaker, the signal is input to a microphone detecting the sound of the speaker through variable gain amplifiers, attenuated in variable attenuation units, the peak value of absolute values of differences between the signals of an opposing pair of microphones is detected at level detection units, and a level judgment and gain control unit adjusts the gains of the variable gain amplifiers or attenuation amounts of the variable attenuation units so that the value becomes within a sensitivity difference adjustment error.

Abstract: A two-way communication apparatus used for two-way speech and improved from the viewpoint of the performance, the viewpoint of the price, the viewpoint of the dimensions, and the viewpoints of suitability with the usage environment, user-friendliness, etc. is provided. In the two-way communication apparatus, a plurality of microphones (MC1 to MC6) radially arranged in a horizontal direction are located at equal distances from a receiving and reproduction speaker (16). The plurality of microphones (MC1 to MC6) are located in pairs from the center of the receiving and reproduction speaker (16). Surface of a sound reflection plate (12) facing the side surfaces of a speaker housing (14a) are curved to a flared shape and diffuse the sound output from an upper sound output opening (14c) in all orientations in the horizontal direction by cooperating with the sound reflection surface (14a).

Abstract: A videoconferencing system uses an audio input unit including: two directional microphones disposed in directions with directivity being opposite to each other, the microphones forming a pair and a plurality of the pairs being located with directivity shifted from each other, cancellation elements for canceling sound components of the same phase from sounds inputted to the microphones of the pair, extraction elements for extracting sound components of voice band from sounds inputted to the microphones of the pair, a calculation element for calculating a difference between levels of the sound components of voice band extracted by the extraction elements to decide the microphone which has the larger level in the pair having the largest level difference, and selection elements for selecting sounds as input sound, in which the sound components with the same phase are canceled by the cancellation elements from sound inputted to the microphone decided by the calculation element.

Abstract: A communication apparatus used for two-way speech wherein the acoustic couplings between a speaker and microphones can be made equal by a simple method, wherein radially arranged microphones are located at equal distances from a speaker, a test signal generation unit outputs a pink noise signal to the speaker, the signal is input to a microphone detecting the sound of the speaker through variable gain amplifiers, attenuated in variable attenuation units, the peak value of absolute values of differences between the signals of an opposing pair of microphones is detected at level detection units, and a level judgment and gain control unit adjusts the gains of the variable gain amplifiers or attenuation amounts of the variable attenuation units so that the value becomes within a sensitivity difference adjustment error.

Abstract: A speaker system enabling efficient dispersion of intelligible sound far in all directions from a specific point along a certain planar direction, provided with a single speaker, a first reflective (directing) surface arranged facing a sound output direction of the speaker and reflecting the sound to directions different from the output direction, and a second reflective (directing) surface arranged facing the first reflective surface, wherein the distance between the first reflective surface and the second reflective surface increases continuously in proportion to the distance from the center of the speaker and wherein the first reflective surface and the second reflective surface diffuse sound radially from the speaker to directions different to the sound output direction of the speaker.

Abstract: A videoconferencing system uses an audio input unit including: two directional microphones disposed in directions with directivity being opposite to each other, the microphones forming a pair and a plurality of the pairs being located with directivity shifted from each other, cancellation elements for canceling sound components of the same phase from sounds inputted to the microphones of the pair, extraction elements for extracting sound components of voice band from sounds inputted to the microphones of the pair, a calculation element for calculating a difference between levels of the sound components of voice band extracted by the extraction elements to decide the microphone which has the larger level in the pair having the largest level difference, and selection elements for selecting sounds as input sound, in which the sound components with the same phase are canceled by the cancellation elements from sound inputted to the microphone decided by the calculation element.