Abstract
Sound plays a vital role in various aspects of everyday life, including human communication, industrial
monitoring, and medical diagnosis. Although sound is generally measured using microphones, research
on optical sound measurements have recently progressed. This paper reviews the overview of optical
sound measurement to date and describes a method for the absolute measurement of sound pressure in air
using an optical frequency comb. Measuring the resonance frequency shift of an optical resonator caused
by sound using the optical comb makes it possible to quantitatively determine the sound pressure.
