The said conversational

摘要

PPROBLEM TO BE SOLVED: To make a masking sound control part of a device for protection of speech privacy emit the minimum separate sound as masking sound over a loudspeaker which does not become obstructive to the periphery of a third party by measuring frequency spectra of speaker's speech, masking sound of the periphery, and background noise detected by microphones, and by controlling a frequency filter of a masking sound generating part so that both frequency spectra become equal. PSOLUTION: The speech privacy protective device comprises: a mixer which detects speakers' voices and mixes the speakers' voices detected by microphones by a masking sound control part; a frequency analyzer for measuring a frequency spectrum of the mixed voices; and a frequency analyzer for measuring the frequency spectra of the masking sound and the background noise in the periphery of the speakers, and controls the frequency filter of the masking sound generating part by a control circuit so that the frequency spectrum of the masking sound and the background noise becomes equal to the frequency spectrum of the voices, and emits the minimum separate sound matched with the frequency spectrum of the speakers' voices over the loudspeaker as masking sound. PCOPYRIGHT: (C)2007,JPO&INPIT