If a pitch from a moving vehicle sounds lower to a hearer, where is the vehicle in relation to the hearer? a. past the hearer b. before the hearer c. above the level of the hearer’s ear d. below the level of the hearer’s ear

The appropriate answer is a. past the hearer. The question is describing the doppler effect. This refers to the change in the frequency or the wavelength of a sound relative to an observer. The object creating the sound must be moving relative to the hearer. When the car approaches the pitch will get higher and as it passes and is moving away the pitch will get lower.