The paper embodies the results of an experimental investigation carried out to study noise of a relatively new type of
gearing of double circular-arc tooth- profile. More than 300 magnetic tape recordings were taken and analysedsfor gears
4 mm module running at different speeds and loads in a direct drive gear test rig installed in free field. Experimental results revealed that the largest single frequency component is double the tooth contact frequency and that patterns of the generalised generated noise are uniform in all directions. Generally, as either speed or load increases, overall noise levels increase from 95 dB at speed 400 r.p.m. and load =15kp to 115 dB at speed 2250 r.p.m. and load= 40kp.