Nara Institute of Science and Technology

Toyota Jidosha Kabushiki Kaisha

Kiyohiro Shikano

Narimasa Watanabe

Tomoki Toda

Mikihiro Nakagiri

Hideki Kashioka

Randy Gomez

A processing unit is provided which executes speech recognition on speech signals captured by a microphone for capturing sounds uttered in an environment. The processing unit has: an initial reflection component extraction portion that extracts initial reflection components by removing diffuse reverberation components from a reverberation pattern of an impulse response generated in the environment; and an acoustic model learning portion that learns an acoustic model for the speech recognition by reflecting the initial reflection components to speech data for learning.

Processing unit, speech recognition apparatus, speech recognition system, speech recognition method, storage medium storing speech recognition program

[Problems] To convert a signal of non-audible murmur obtained through an in-vivo conduction microphone into a signal of a speech that is recognizable for (hardly misrecognized by) a receiving person with maximum accuracy. [Means for Solving Problems] A speech processing method comprising: a learning step (S) for conducting a learning calculation of a model parameter of a vocal tract feature value conversion model indicating conversion characteristic of acoustic feature value of vocal tract, on the basis of a learning input signal of non-audible murmur recorded by an in-vivo conduction microphone and a learning output signal of audible whisper corresponding to the learning input signal recorded by a prescribed microphone, and then, storing a learned model parameter in a prescribed storing means; and a speech conversion step (S) for converting a non-audible speech signal obtained through an in-vivo conduction microphone into a signal of audible whisper, based on a vocal tract feature value conversion model, with a learned model parameter obtained through the learning step set thereto.

Apparatus and method for producing an audible speech signal from a non-audible speech signal

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Ikoma, Japan

Kiyohiro Shikano