Voice conference equipment

Abstract

Abstract PURPOSE:To progress a conference smoothly by providing a gain control circuit inserting a variable gain circuit to each output of plural microphones and varying the gain of the variable gain circuit in response to the output voice signal level of the corresponding microphone so as to generate a voice with sufficient sound volume from a speaker even when the speaker and the microphone are approached. CONSTITUTION:Gain variable circuits 13a, 13b are controlled to a gain where an input level to an adder circuit 8 is a reference value or below independently of the acoustic coupling condition with corresponding microphones 6a, 6b and a speaker 5. Then the reference value used for a control circuit 12 is made correspondent to a cancel enable level of a bypass component in an echo cancellation circuit 2 to ensure the cancellation of the bypass component independently of the acoustic coupling condition between the microphones 6a, 6b and the speaker 5. In this case, the sound volume of the speaker 5 is fixed to the gain set in the amplifier circuit 4, then the voice from the opposite party is sounded with a sufficient sound volume.

Inventors

• 👤 Shoji Makino
• 👤 Nobuo Koizumi
• 👤 Mizuhiro Hida
• 👤 Naohide Kushige
• 👤 Takashi Saeki
• 👤 Shigenobu Minami

Bibliographic Details