What are the two basic aspects to consider for every sound wave?

• A. Frequency and amplitude
• B. Amplitude and wavelength
• C. Frequency and wavelength
• D. Speed and duration

Answer: (A)

Frequency and amplitude are the two basic aspects that define a sound wave. Frequency tells us how often the pressure fluctuations occur each second, which we perceive as pitch—the higher the frequency, the higher the pitch. Amplitude describes how big those fluctuations are, which we hear as loudness—the greater the amplitude, the louder the sound. Wavelength, speed, or duration involve other properties of how a wave travels or persists, but the direct qualities of the sound itself in terms of how we hear it are set by frequency and amplitude.