Abstract
Low frequency noise is not clearly defined but is generally taken to mean noise below a frequency of about 100 Hz. Noise occurring at frequencies below 20Hz is often referred to as infrasound and this type of noise presents even greater difficulties in its countermeasure and assessment. The objective of our study is to suggest practical means of reducing the low frequency noise emanating from the opening of soundproof houses. This paper describes an experimental study on the alleviation of low frequency noise by the standing wave control in a soundproof house. As a result, about 3dB of low frequency noise reduction has been achieved at the reference point over a 1/3 octave band range of 200 Hz, which is the conversion frequency of 16 Hz for a real soundproof house. In the case of combination, the standing wave control and expansion type silencer, maximum noise reduction has been reduced by about 12 dB.
