The communication device

PROBLEM TO BE SOLVED: To provide a telephone call device capable of surely preventing howling from occurring. SOLUTION: In a microphone M1, a vibration portion 53c is arranged toward a speaker SP. In a microphone M2, the vibration portion 53c is arranged in the same direction as the output direction of the speaker SP. A signal processing section stored in an IC package 35i comprises a level adjustment means for performing level adjustment, corresponding to the difference of each distance between the microphones M1, M2, and the speaker SP to allow each output level of the microphones M1, M2 to sound from the speaker SP to match; a delay means for delaying sound signal according to the transmission time of sound waves, corresponding to the difference between distances X1, X2 of the microphones M1, M2 and the speaker SP for allowing the phase of each sound signal of the microphones M1, M2 to match; and a differential means for outputting the difference of the sound signal between the microphones M1, M2 passing through the level adjustment and delay means. COPYRIGHT: (C)2007,JPO&INPIT