A new microphone system for near whispering.
A new microphone system was developed to monitor the human voice near the microphone in a noisy environment. The system is equipped with two special functions in addition to the usual microphone functions: reduction of air-blow effects by the mouth and focused reception to a sound source. A wind filter was developed to reduce the air-blow effects from the mouth during speaking. This filter is a plate perforated by an array of small holes; the method used to design the filter is also presented. To achieve focused reception, four microphones were used in conjunction with a new signal-processing method. The proposed signal-processing method effectively increases the directivity in the desired direction. Additionally, it provides the system with focusing on the source since the source is located adjacent to the system. A prototype of the proposed system was fabricated and subjected to performance tests. The results showed that air-blow effects can be reduced by up to 20 dB and the directional gain is more than 4 dB. The proposed microphone system shows such good performance that it can be used in mobile phones for whispering communication.
Choi
Sungjoon
S
Department of Mechanical Engineering, Pohang University of Science and Technology, San 31, Hyojadong Namgu, Pohang, Kyungbuk 790-784, South Korea.
Moon
Wonkyu
W
Lee
Jeong Hyun
JH
D000161:Acoustic Stimulation; D000669:Amplifiers, Electronic; D006801:Humans; D008954:Models, Biological; D013060:Speech; D014831:Voice