| 摘要 |
PROBLEM TO BE SOLVED: To reduce the wind sound noise of a signal picked up by a single channel. SOLUTION: An audio signal picked up by a microphone 1 is inputted through a preamplifier 2, an automatic gain control circuit 3 and an analog/digital converter 4 to a wind sound reduction circuit 10. Then, the inputted digital audio signal is inputted to a first wind sound reduction means equal to or lower than 1 kHz composed of a low-pass filter (LPF) H, a delay circuit 12, an adder 13 and a variable gain amplifier 14 and further inputted to a second wind sound reduction means equal to or lower than 100 Hz composed of an LPF 15, a delay circuit 16, an adder 17 and a variable gain amplifier 18. Besides, the digital audio signal is inputted through a low frequency band dividing means 19 to a mutual correlation coefficient calculating means 20 and a calculated mutual correlation coefficient is inputted to a time constant adding circuit 21 of the gain control part of the variable gain amplifier 18 and further inputted through an attenautor 22 to the gain control part of the variable gain amplifier 14. |
