Engine Noise Testing in an Economical “Semi” Anechoic Room

A “semi” anechoic room design has been proposed and constructed from readily available, inexpensive construction materials. To demonstrate its feasibility, noise testing was conducted using a rotary engine as the noise source.

The results of the testing indicated that the design is functional since free field conditions exist. This condition was proven to exist for at least one angular position measured relative to the exhaust pipe and in the horizontal plane of the exhaust pipe. Other information is provided concerning engine behaviour and type of noise radiated.