Patent ID: 7315819

Claim:
An information detection apparatus for detecting predetermined information from coded speech data coded by a speech coding method using spectrum analysis and for identifying and verifying a current speaker, said information detection apparatus comprising: spectral information decoding means for decoding spectral information from said coded speech data; speaker identification means for identifying a most likely speaker amongst a plurality of possible speakers on the basis of said decoded spectral information; and verification means for verifying that the most likely speaker actually is the current speaker by setting an average quantized distortion of the most likely speaker as D 0 , determining the averaged quantized distortions of “n” speakers other than the most likely speaker, determining a distortion difference ΔD using one of the following two equations: a ) ⁢ ⁢ Δ ⁢ ⁢ D = ∑ j = 1 n ⁢ ⁢ D j - D 0 b ) ⁢ ⁢ Δ ⁢ ⁢ D = 1 n ⁢ ∑ j = 1 n ⁢ ⁢ D j - D 0 reading threshold data associated with the most likely speaker including the maximum absolute distortion D max of quantized distortion, and a minimum distortion difference D min which had been recorded in advance, and finally outputting a determination that the most likely speaker is the current speaker if (D 0 <Dmax) and (ΔD>Dmin).