Development of a weatherproof windscreen for a microphone array

摘要

This paper presents the development of a windscreen used on an array of five microphones located around a 0.1143-meter (4.5-inch) cylinder. The design criteria consisted of having a wind noise attenuation of at least 8 dB at 20.9 km/h (13 mph), an insertion loss of less than 1 dB from 50 to 1000 Hz, a phase shift error between each microphone of less than 3% over the same frequency range, and the ability to protect the array from natural elements such as sand and other debris. Computer simulations and experimental testing were employed to select two basic designs. The first design consists of two foam-filled concentric cones set around the microphone array. The second design consists of tubes that project outward from each microphone and then curve downwards. Both final windscreen designs meet the desired requirements. They both reduce wind noise by approximately 9 dB in a 20.9 km/h (13 mph) wind and over 16 dB in a 32.2 km/h (20 mph) wind. They also have negligible insertion loss, have a phase shift error of less than 3%, and are very efficient at blocking particles from entering the windscreen. (C) Institute of Noise Control Engineering.