Answer:
Frequency
Step-by-step explanation:
Frequency is the number of oscillations (cycles or repetitions of the wave) that occur in wave in one second and is measured in hertz (Hz). Higher-frequency sound waves have a higher pitch, and lower-frequency sound waves have a lower pitch.
The frequency of a wave has an affect on the air pressure and our ears are incredibly sensitive and can detect these changes in air pressure, so when a low-frequency wave hits our ears, our brain processes this low-frequency wave and can perceive a longer time interval between each cycle of the wave. Therefore the sound you hear from the low-frequency wave has a low-pitch