Final answer:
When waves are closely spaced, the pitch changes. In the case of sound waves, when the wavelength is shorter (waves are closely spaced), the frequency is higher and therefore the pitch is higher. Conversely, when the wavelength is longer (waves are farther apart), the frequency is lower and the pitch is lower.
Step-by-step explanation:
When waves are closely spaced, the pitch changes. In the case of sound waves, when the wavelength is shorter (waves are closely spaced), the frequency is higher and therefore the pitch is higher. Conversely, when the wavelength is longer (waves are farther apart), the frequency is lower and the pitch is lower. This is because pitch is determined by frequency, with higher frequencies corresponding to higher pitches and lower frequencies corresponding to lower pitches.