sonometer
/ˈsɑːnoʊmɛtər/Definitions
1. noun
An instrument used to measure the velocity of sound, usually by the time it takes for a sound to travel a known distance and be reflected back.
“The scientist used a sonometer to measure the speed of sound in the dense fog.”
2. noun
A device that measures the frequency of a sound, typically used in physics and engineering.
“The physicist employed a sonometer to analyze the wave pattern of the guitar string.”