Nippon Telegraph and Telephone Corporation

Sachiko Kurihara

Noboru Harada

Shinji Hayashi

Masahiro Fukui

Akira Nakagawa

Akitoshi Kataoka

The number of conversational tests required for evaluation of acoustic quality of the ICC system is reduced. An evaluation value converting deviceevaluates the quality of a conversation made across a near-end acoustic areaand a far-end acoustic areainside a vehicle in which a plurality of acoustic areas are predetermined. A voice signal collected by a microphone Mdisposed in the far-end acoustic areais emitted from a speaker Sdisposed in the near-end acoustic area. An objective evaluation value acquisition unitacquires an evaluation value using, as an evaluation target sound, a voice signal obtained by adding a voice signal obtained from a first voice signal emitted from a sound source in the far-end acoustic area, collected by the microphone M, and emitted from the speaker Sto a voice signal obtained from the first voice signal transmitted through a space inside the vehicle and reaching the near-end acoustic area, with the first voice signal being used as a reference sound.

Evaluation apparatus, evaluation method, and program

The number of conversational tests needed for the evaluation of acoustic quality of the ICC system is reduced. An evaluation value conversion deviceevaluates the quality of communication between a near-end acoustic regionand a far-end acoustic regioninside a vehicle for which a plurality of acoustic regions are predetermined. A voice signal picked up by a microphone Mdisposed in the far-end acoustic regionis emitted from a speaker Sdisposed in the near-end acoustic region. An objective evaluation value acquisition unitacquires a first evaluation value by treating a voice signal obtained by combining a voice signal resulting from a first voice signal being emitted from a sound source in a seat belonging to the far-end acoustic region, picked up by the microphone M, and emitted from the speaker Swith a voice signal arriving at a seat belonging to the near-end acoustic regionas a result of the first voice signal being transmitted through the space inside the vehicle as an evaluation target sound, and treating the first voice signal as a reference sound. An evaluation value reuse unitacquires the first evaluation value as an evaluation value of communication between a seat belonging to the near-end acoustic regionand a seat belonging to the far-end acoustic region

Evaluation method, evaluation apparatus, and program

To improve accuracy of an evaluation in an acoustic quality evaluation test performed by comparing an evaluation target sound and a reference sound. A data correction apparatuscompares, in a call performed between a near-end terminaland a far-end terminal, an evaluation target sound in which a voice output from the near-end terminalis recorded and a reference sound in which a voice spoken by a call partner using the far-end terminalto correct test data used in a listening test for evaluating acoustic quality of the call. A correction target determination unitdetermines, as a correction target section, a voiced section that does not include the voice of the call partner detected from an acoustic signal representing the reference sound. A correction execution unitupdates the correction target section of the acoustic signal representing the reference sound with a non-voice signal predetermined.

Data correction apparatus, data correction method, and program

To obtain an appropriate evaluation value in an acoustic quality evaluation by a conversational test. An acoustic quality evaluation apparatusevaluates the acoustic quality of a call performed between a near-end terminaland a far-end terminalvia a voice communication network. An evaluation value presenting unitdisplays, on a display unit, evaluation categories obtained by classifying each of a plurality of evaluation viewpoints into a predetermined number of levels. An input unittransmits the evaluation category selected by the evaluator for each of the evaluation viewpoints, to an evaluation value determination unit. The evaluation value determination unitdetermines the lowest evaluation value among evaluation values assigned to the evaluation category received from the input unitas a subjective evaluation value for acoustic quality.

Acoustic quality evaluation apparatus, acoustic quality evaluation method, and program

An ACELP speech coding method according to ITU-T Recommendation G.729. When coding a random component vector, each of random component vector forming together the random codebook is formed of three or less pulses having a unit amplitude for each 6f a pair of subframes which form together a frame. The positions of the pulses are determined from a plurality of predetermined positions which a pulse can assume in a subframe so that distortion is minimized. The method allows speech coding at a lower bit rate.

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Tokyo, Japan

Sachiko Kurihara