Auditory Representations of Timbre and Pitch

Pitch and timbre are terms developed to describe musical sounds. By convention, pitch is that perceptual property of a sound that can be used to play a melody, while timbre is a rather more vague perceptual property that distinguishes musical sounds of the same pitch. The pitch of an arbitrary sound is quantified as the frequency in hertz (Hz) of a sinusoid with perceptually matching pitch. Thus, one might say that pitch is a perceptual frequency, and timbre is almost everything else (but not including loudness, position, and perhaps a few other well-defined attributes). In general, a sound source achieves a perceptual unity through pitch, and encodes its identity primarily through timbre. For example, any instrument playing middle C will be heard as a sound source with a pitch of 262 Hz, but the timbre of the sound will tell us whether we are hearing a string excited by a bow, or a tube excited by reed, or a vibrating metal bar, or an electronically synthesized buzz.