Whats the difference between frequency and shrillness ?

Frequency is the number of vibrations in a unit time. It is measured in Hertz (Hz).Shrillness is also called pitch. The frequency determines the shrillness or the pitch of a sound. Frequency is directly proportional to the shrill

If the frequency of a vibration is higher we say that the sound is shrill and has a higher pitch. For Example, the sound of a whistle.

If the frequency of vibration is lower, we say that the sound has a lower pitch and is less shrill. For Example, the sound of a drum.