The music scale "do, re, mi, fa, so, la, ti, do" starts with a low sound and becomes higher with each note. What property of sound is changing when this happens?
The frequency of any kind of wave is the inverse of the time interval between successive “crests” (maxima) of the wave (or between successive “troughs” [minima]).
Frequency is a measure of the tone or pitch of sound. It’s measured in Hertz (or “Cycles” in the old days).
Humans can hear from about 20 Hz to 20,000 hz (aka 20 KHz) unless you’re old like me and can hear from about 30 Hz to 15 KHz on a good day.
Hence, the correct answer is "frequency of sound is changing when this happen"
