NASA Technical Memorandum 100155; AVSCOM Technical Report 87-C-24
Acoustic intensity measurements were made at NASA Lewis Research Center on a spur gear test apparatus. The measurements were obtained with the Robotic Acoustic Intensity Measurement System developed by Cleveland State University. This system provided dense spatial positioning, and was calibrated against a high quality acoustic intensity system. The measured gear noise compared gearsets having two different tooth profiles. The tests evaluated the sound field of the different gears for two speeds and three loads. The experimental results showed that gear tooth profile had a major effect on measured noise. Load and speed were found to have an effect on noise also.
Atherton, William J.; Pintz, Adam; and Lewicki, David G., "Automated Acoustic Intensity Measurements and the Effect of Gear Tooth Profile on Noise" (1987). Mechanical Engineering Faculty Publications. 4.