As the source of sound moves towards an observer, the frequency of the sound waves will increase, causing the pitch of the sound to appear higher. Conversely, as the source moves away from the observer, the frequency of the sound waves will decrease, causing the pitch of the sound to appear lower. This phenomenon is known as the Doppler effect. Additionally, the intensity of the sound may also appear to change as the source moves, due to changes in the distance between the source and the observer.
