HR: 0830h
AN: U31B-0017    [PDF]
TI: Infrasound Noise Reduction using Inexpensive Microphones
AU: * Hayward, C
EM: hayward@smu.edu
AF: Department of Geosciences Southern Methodist University, Dedman College PO Box 0395, Dallas, TX 75275 United States
AB: Inexpensive consumer microphones with noise canceling backs may be converted to infrasound microphones with the addition of a simple backing volume built from common PVC plumbing. By using a large number of elements within each microphone, instrument 0.5-5 Hz self-noise may be reduced to below ambient background levels for many locations. Such instruments have now been field tested for nearly 1 year in a 4 element mini-array. Instrument responses of the present implementation vary such that each instrument requires an individual instrument correction curve. Determining instrument response is done by comparison with a reference microphone using ambient laboratory noise. As an alternative to infrasound noise reduction using large passive pipe arrays or other passive geometries, small arrays of inexpensive microphones may be used to coherently improve infrasound signals. While this does not completely eliminate the need for passive pipe systems, it does provide an enhanced ability to acquire infrasound signals in the presence of noise.
DE: 0394 Instruments and techniques
DE: 7294 Instruments and techniques
DE: 8494 Instruments and techniques
SC: U
MN: 2003 Fall Meeting