Final answer:
Yes, the Doppler effect occurs when the source and observer are moving towards each other, resulting in an increase in the perceived frequency or pitch. This is due to the waves reaching the observer at a shorter interval, resulting in a higher frequency being heard. The effect is more pronounced when both are moving towards each other compared to when only one is moving.
Step-by-step explanation:
The Doppler effect does occur when the source and observer are both moving towards each other. This scenario indeed affects the perceived frequency of the sound. When there is relative motion between the source and the observer towards each other, the perceived frequency increases. This is because the waves are reaching the observer at a shorter interval than if the source was stationary, leading to a higher pitch or frequency heard by the observer.
As an example, consider an ambulance with a siren moving towards you. You will hear a higher frequency or pitch of the siren until it passes you, after which the frequency or pitch drops. This change in frequency or pitch due to the relative motion between the source of the sound and the observer is referred to as a Doppler shift. The greater the relative speed of either the observer or the source, the greater the shift in frequency will be.
Furthermore, if both the source and observer are moving towards each other, the effect on the frequency is more pronounced than if only one was moving. However, if the source is moving at or above the speed of sound, unusual phenomena such as sonic booms occur because sound waves are piling up and reaching the observer simultaneously. For everyday situations involving subsonic speeds, the principle that relative motion towards each other produces a higher observed frequency remains true.