The difference between pitch and volume is that pitch is determined by the frequency that sound waves vibrate at while volume measures how loud or soft sound is. Combined with timbre, pitch, measured in hertz, and volume, measured in decibels, comprise the three components of sound.
A sound’s pitch is produced by a vibrating object that moves the air at a certain frequency. Usually expressed in hertz or kilohertz, pitch is used to tune musical instruments, to test hearing and in many industries to activate machinery, sound alarms, etc. Normal human hearing can detect pitches from 20Hz to 20KHz, where one Hz equals one sound vibration per second. Depending on an individual’s hearing, only some pitches may be audible at a given volume.
The volume of sound measures intensity of sound, which the human ear perceives as loudness. Because sound waves are also pressure waves, measuring volume, or loudness and intensity, depends on both their SPL and the duration of a sound. Decibels, used to measure sound intensity, are logarithmic measures that express the ratio between two values of a physical quantity, as in the power or intensity of sound. For example, making a sound two times louder increases its volume in decibels by 10 decibels.