Timbre
In music, timbre (/ˈtæmbər, ˈtɪm-, ˈtæ̃-/), also known as tone color or tone quality (from psychoacoustics), is the perceived sound quality of a musical note, sound or tone. Timbre distinguishes different types of sound production, such as choir voices and musical instruments. It also enables listeners to distinguish different instruments in the same category (e.g., an oboe and a clarinet, both woodwind instruments).
For other uses, see Timbre (disambiguation).
In simple terms, timbre is what makes a particular musical instrument or human voice have a different sound from another, even when they play or sing the same note. For instance, it is the difference in sound between a guitar and a piano playing the same note at the same volume. Both instruments can sound equally tuned in relation to each other as they play the same note, and while playing at the same amplitude level each instrument will still sound distinctively with its own unique tone color. Experienced musicians are able to distinguish between different instruments of the same type based on their varied timbres, even if those instruments are playing notes at the same fundamental pitch and loudness.
The physical characteristics of sound that determine the perception of timbre include frequency spectrum and envelope. Singers and instrumental musicians can change the timbre of the music they are singing/playing by using different singing or playing techniques. For example, a violinist can use different bowing styles or play on different parts of the string to obtain different timbres (e.g., playing sul tasto produces a light, airy timbre, whereas playing sul ponticello produces a harsh, even and aggressive tone). On electric guitar and electric piano, performers can change the timbre using effects units and graphic equalizers.
Synonyms[edit]
Tone quality and tone color are synonyms for timbre, as well as the "texture attributed to a single instrument". However, the word texture can also refer to the type of music, such as multiple, interweaving melody lines versus a singable melody accompanied by subordinate chords. Hermann von Helmholtz used the German Klangfarbe (tone color), and John Tyndall proposed an English translation, clangtint, but both terms were disapproved of by Alexander Ellis, who also discredits register and color for their pre-existing English meanings.[1] Determined by its frequency composition, the sound of a musical instrument may be described with words such as bright, dark, warm, harsh, and other terms. There are also colors of noise, such as pink and white. In visual representations of sound, timbre corresponds to the shape of the image,[2] while loudness corresponds to brightness; pitch corresponds to the y-shift of the spectrogram.
ASA definition[edit]
The Acoustical Society of America (ASA) Acoustical Terminology definition 12.09 of timbre describes it as "that attribute of auditory sensation which enables a listener to judge that two nonidentical sounds, similarly presented and having the same loudness and pitch, are dissimilar", adding, "Timbre depends primarily upon the frequency spectrum, although it also depends upon the sound pressure and the temporal characteristics of the sound".[3]
Psychoacoustic evidence[edit]
Often, listeners can identify an instrument, even at different pitches and loudness, in different environments, and with different players. In the case of the clarinet, acoustic analysis shows waveforms irregular enough to suggest three instruments rather than one. David Luce suggests that this implies that "[C]ertain strong regularities in the acoustic waveform of the above instruments must exist which are invariant with respect to the above variables".[11] However, Robert Erickson argues that there are few regularities and they do not explain our "...powers of recognition and identification." He suggests borrowing the concept of subjective constancy from studies of vision and visual perception.[12]
Psychoacoustic experiments from the 1960s onwards tried to elucidate the nature of timbre. One method involves playing pairs of sounds to listeners, then using a multidimensional scaling algorithm to aggregate their dissimilarity judgments into a timbre space. The most consistent outcomes from such experiments are that brightness or spectral energy distribution,[13] and the bite, or rate and synchronicity[14] and rise time,[15] of the attack are important factors.
Brightness[edit]
The term "brightness" is also used in discussions of sound timbres, in a rough analogy with visual brightness. Timbre researchers consider brightness to be one of the perceptually strongest distinctions between sounds,[14] and formalize it acoustically as an indication of the amount of high-frequency content in a sound, using a measure such as the spectral centroid.