10.2 Complex Sounds

Harmonic Spectrum

The pattern of harmonics (frequencies) that make up a complex sound. It shows the different frequencies and their relative strengths in a sound.

Fundamental Frequency

The lowest frequency in a harmonic series and the frequency that determines the sound’s pitch. Even when the fundamental is missing, listeners can still hear its pitch, called the missing fundamental or phantom fundamental.

Timbre

The quality or character of a sound that allows us to tell two sounds apart even when they have the same pitch and loudness. For example, a violin and a piano can play the same note at the same loudness but still sound different because they have different timbres.

Attack

The beginning of a sound, including how quickly the sound reaches its maximum loudness after it starts.

Decay

The decrease in a sound’s loudness after the attack. How quickly it decays depends on how quickly the vibrating object loses energy and stops moving.