Pitch is a perceptual property that allows the ordering of sounds on a frequency-related scale.[1] Pitches are compared as higher and lower in the sense associated with musical melodies,[2] which require sound whose frequency is clear and stable enough to distinguish from noise.[3] Pitch is a major auditory attribute of musical tones, along with duration, loudness, and timbre.[4] Pitch may be quantified as a frequency, but pitch is not a purely objective physical property; it is a subjective psychoacoustical attribute of sound. Historically, the study of pitch and pitch perception has been a central problem in psychoacoustics, and has been instrumental in forming and testing theories of sound representation, processing, and perception in the auditory system.[5] Contents [hide] 1 Perception of pitch 1.1 Pitch and frequency 1.2 Theories of pitch perception 1.3 Just-noticeable difference 1.4 Aural illusions 2 Definite and indefinite pitch 3 Concert pitch 4 Labeling pitches 5 Scales 6 Other musical meanings of pitch 7 See also 8 References 9 Further reading 10 External links Perception of pitch[edit] Pitch and frequency[edit] Pitch is an auditory sensation in which a listener assigns musical tones to relative positions on a musical scale based primarily on the frequency of vibration.[6] Pitch is closely related to frequency, but the two are not equivalent. Frequency is an objective, scientific concept, whereas pitch is subjective. Sound waves themselves do not have pitch, and their oscillations can be measured to obtain a frequency. It takes a human mind to map the internal quality of pitch. Pitches are usually quantified as frequencies in cycles per second, or hertz, by comparing sounds with pure tones, which have periodic, sinusoidal waveforms. Complex and aperiodic sound waves can often be assigned a pitch by this method.[7][8][9] According to the American National Standards Institute, pitch is the auditory attribute of sound according to which sounds can be ordered on a scale from low to high. Since pitch is such a close proxy for frequency, it is almost entirely determined by how quickly the sound wave is making the air vibrate and has almost nothing to do with the intensity, or amplitude, of the wave. That is, high pitch means very rapid oscillation, and low pitch corresponds to slower oscillation. Despite that, the idiom relating vertical height to sound pitch is shared by most languages.[10] At least in English, it is just one of many deep conceptual metaphors that involve up/down. The exact etymological history of the musical sense of high and low pitch is still unclear. There is evidence that humans do actually perceive that the source of a sound is slightly higher or lower in vertical space when the sound frequency is increased or decreased.[10] In most cases, the pitch of complex sounds such as speech and musical notes corresponds very nearly to the repetition rate of periodic or nearly-periodic sounds, or to the reciprocal of the time interval between repeating similar events in the sound waveform.[8][9] The pitch of complex tones can be ambiguous, meaning that two or more different pitches can be perceived, depending upon the observer.[5] When the actual fundamental frequency can be precisely determined through physical measurement, it may differ from the perceived pitch because of overtones, also known as upper partials, harmonic or otherwise. A complex tone composed of two sine waves of 1000 and 1200 Hz may sometimes be heard as up to three pitches: two spectral pitches at 1000 and 1200 Hz, derived from the physical frequencies of the pure tones, and the combination tone at 200 Hz, corresponding to the repetition rate of the waveform. In a situation like this, the percept at 200 Hz is commonly referred to as the missing fundamental, which is often the greatest common divisor of the frequencies present.[11] Pitch depends to a lesser degree on the sound pressure level (loudness, volume) of the tone, especially at frequencies below 1,000 Hz and above 2,000 Hz. The pitch of lower tones gets lower as sound pressure increases. For instance, a tone of 200 Hz that is very loud seems one semitone lower in pitch than if it is just barely audible. Above 2,000 Hz, the pitch gets higher as the sound gets louder.[12] Theories of pitch perception[edit] Theories of pitch perception try to explain how the physical sound and specific physiology of the auditory system work together to yield the experience of pitch. In general, pitch perception theories can be divided into place coding and temporal coding. Place theory holds that the perception of pitch is determined by the place of maximum excitation on the basilar membrane. A place code, taking advantage of the tonotopy in the auditory system, must be in effect for the perception of high frequencies, since neurons have an upper limit on how fast they can phase-lock their action potentials.[6] However, a purely place-based theory cannot account for the accuracy of pitch perception in the low and middle frequency ranges. Temporal theories offer an alternative that appeals to the temporal structure of action potentials, mostly the phase-locking and mode-locking of action potentials to frequencies in a stimulus. The precise way this temporal structure helps code for pitch at higher levels is still debated, but the processing seems to be based on an autocorrelation of action potentials in the auditory nerve.[13] However, it has long been noted that a neural mechanism that may accomplish a delay—a necessary operation of a true autocorrelation—has not been found.[6] At least one model shows that a temporal delay is unnecessary to produce an autocorrelation model of pitch perception, appealing to phase shifts between cochlear filters;[14] however, earlier work has shown that certain sounds with a prominent peak in their autocorrelation function do not elicit a corresponding pitch percept,[15][16] and that certain sounds without a peak in their autocorrelation function nevertheless elicit a pitch.[17][18] To be a more complete model, autocorrelation must therefore apply to signals that represent the output of the cochlea, as via auditory-nerve interspike-interval histograms.[16] Some theories of pitch perception hold that pitch has inherent octave ambiguities, and therefore is best decomposed into a pitch chroma, a periodic value around the octave, like the note names in western music, and a pitch height, which may be ambiguous, indicating which octave the pitch may be in.[5] Just-noticeable difference[edit] The just-noticeable difference (jnd) (the threshold at which a change is perceived) depends on the tones frequency content. Below 500 Hz, the jnd is about 3 Hz for sine waves, and 1 Hz for complex tones; above 1000 Hz, the jnd for sine waves is about 0.6% (about 10 cents).[19] The jnd is typically tested by playing two tones in quick succession with the listener asked if there was a difference in their pitches.[12] The jnd becomes smaller if the two tones are played simultaneously as the listener is then able to discern beat frequencies. The total number of perceptible pitch steps in the range of human hearing is about 1,400; the total number of notes in the equal-tempered scale, from 16 to 16,000 Hz, is 120.[12] Aural illusions[edit] The relative perception of pitch can be fooled, resulting in aural illusions. There are several of these, such as the tritone paradox, but most notably the Shepard scale, where a continuous or discrete sequence of specially formed tones can be made to sound as if the sequence continues ascending or descending forever. Definite and indefinite pitch[edit] Not all musical instruments make notes with a clear pitch. The unpitched percussion instrument class of percussion instrument do not produce particular pitches. A sound or note of definite pitch is one where a listener can possibly (or relatively easily) discern the pitch. Sounds with definite pitch have harmonic frequency spectra or close to harmonic spectra.[12] A sound generated on any instrument produces many modes of vibration that occur simultaneously. A listener hears numerous frequencies at once. The vibration with the lowest frequency is called the fundamental frequency; the other frequencies are overtones.[20] Harmonics are an important class of overtones with frequencies that are integer multiples of the fundamental. Whether or not the higher frequencies are integer multiples, they are collectively called the partials, referring to the different parts that make up the total spectrum. A sound or note of indefinite pitch is one that a listener finds impossible or relatively difficult to identify as to pitch. Sounds with indefinite pitch do not have harmonic spectra or have altered harmonic spectra a characteristic known as inharmonicity. It is still possible for two sounds of indefinite pitch to clearly be higher or lower than one another. For instance, a snare drum sounds higher pitched than a bass drum though both have indefinite pitch, because its sound contains higher frequencies. In other words, it is possible and often easy to roughly discern the relative pitches of two sounds of indefinite pitch, but sounds of indefinite pitch do not neatly correspond to any specific pitch. A special type of pitch often occurs in free nature when sound reaches the ear of an observer directly from the source, and also after reflecting of a sound-reflecting surface. This phenomenon is called repetition pitch, because the addition of a true repetition of the original sound to itself is the basic prerequisite. Concert pitch[edit] Main article: Concert pitch Concert pitch is the pitch reference a group of musical instruments are tuned to for a performance. Concert pitch may vary from ensemble to ensemble, and has varied widely over musical history. 440 Hz MENU0:00 Problems playing this file? See media help. The A above middle C is usually set at 440 Hz (often written as A = 440 Hz or sometimes A440), although other frequencies are also often used, such as 442 Hz. Historically, this A has been tuned to a variety of higher and lower pitches. Transposing instruments conventionally have their parts transposed into different keys from voices and other instruments (and even from each other). As a result, musicians need a way to refer to a particular pitch in an unambiguous manner when talking to each other. For example, the most common type of clarinet or trumpet, when playing a note written in their part as C, sounds a pitch that is called B♭ on a non-transposing instrument like a piano. If you want to refer to that pitch unambiguously, you call it concert B♭, meaning, ...the pitch that someone playing a non-transposing instrument like a piano calls B♭. Labeling pitches[edit] Question book-new.svg This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (February 2011) For a comprehensive list of frequencies of musical notes, see Scientific pitch notation and Frequencies of notes. Note frequencies, four-octave C major diatonic scale, starting with C1. Pitches are labeled using: Letters, as in Helmholtz pitch notation A combination of letters and numbers—as in scientific pitch notation, where notes are labelled upwards from C0, the 16 Hz C Number that represent the frequency in hertz (Hz), the number of cycles per second For example, one might refer to the A above middle C as a, A4, or 440 Hz. In standard Western equal temperament, the notion of pitch is insensitive to spelling: the description G4 double sharp refers to the same pitch as A4; in other temperaments, these may be distinct pitches. Human perception of musical intervals is approximately logarithmic with respect to fundamental frequency: the perceived interval between the pitches A220 and A440 is the same as the perceived interval between the pitches A440 and A880. Motivated by this logarithmic perception, music theorists sometimes represent pitches using a numerical scale based on the logarithm of fundamental frequency. For example, one can adopt the widely used MIDI standard to map fundamental frequency, f, to a real number, p, as follows p = 69 + 12\times\log_2 { \left(\frac {f}{440\; \mbox{Hz}} \right) } This creates a linear pitch space in which octaves have size 12, semitones (the distance between adjacent keys on the piano keyboard) have size 1, and A440 is assigned the number 69. (See Frequencies of notes.) Distance in this space corresponds to musical intervals as understood by musicians. An equal-tempered semitone is subdivided into 100 cents. The system is flexible enough to include microtones not found on standard piano keyboards. For example, the pitch halfway between C (60) and C♯ (61) can be labeled 60.5. Scales[edit] The relative pitches of individual notes in a scale may be determined by one of a number of tuning systems. In the west, the twelve-note chromatic scale is the most common method of organization, with equal temperament now the most widely used method of tuning that scale. In it, the pitch ratio between any two successive notes of the scale is exactly the twelfth root of two (or about 1.05946). In well-tempered systems (as used in the time of Johann Sebastian Bach, for example), different methods of musical tuning were used. Almost all of these systems have one interval in common, the octave, where the pitch of one note is double the frequency of another. For example, if the A above middle C is 440 Hz, the A an octave above that is 880 Hz (info). Other musical meanings of pitch[edit] In atonal, twelve tone, or musical set theory a pitch is a specific frequency while a pitch class is all the octaves of a frequency. In many analytic discussions of atonal and post-tonal music, pitches are named with integers because of octave and enharmonic equivalency (for example, in a serial system, C♯ and D♭ are considered the same pitch, while C4 and C5 are functionally the same, one octave apart). Discrete pitches, rather than continuously variable pitches, are virtually universal, with exceptions including tumbling strains[21] and indeterminate-pitch chants.[22] Gliding pitches are used in most cultures, but are related to the discrete pitches they reference or embellish.[23] See also[edit] 3rd bridge (harmonic resonance based on equal string divisions) Absolute pitch Diplacusis Eight foot pitch Harmonic pitch class profiles Just intonation Music and mathematics Piano key frequencies Pitch accent Pitch circularity Pitch detection algorithm Pitch of brass instruments Pitch shifter Pitch pipe Relative pitch Scale of vowels Vocal and Instrumental Pitch Ranges References[edit] Jump up ^ Anssi Klapuri and Manuel Davy (2006). Signal processing methods for music transcription. Springer. p. 8. ISBN 978-0-387-30667-4. Jump up ^ Plack, Christopher J.; Andrew J. Oxenham, Richard R. Fay, eds. (2005). Pitch: Neural Coding and Perception. Springer. ISBN 0-387-23472-1. For the purposes of this book we decided to take a conservative approach, and to focus on the relationship between pitch and musical melodies. Following the earlier ASA definition, we define pitch as that attribute of sensation whose variation is associated with musical melodies. Although some might find this too restrictive, an advantage of this definition is that it provides a clear procedure for testing whether or not a stimulus evokes a pitch, and a clear limitation on the range of stimuli that we need to consider in our discussions. Jump up ^ Randel, Don Michael, ed. (2003). The Harvard Dictionary of Music (4 ed.). Harvard University Press. p. 499. ISBN 978-0-674-01163-2. Melody: In the most general case, a coherent succession of pitches. Here pitch means a stretch of sound whose frequency is clear and stable enough to be heard as not noise; succession means that several pitches occur; and coherent means that the succession of pitches is accepted as belonging together. Jump up ^ Roy D. Patterson, Etienne Gaudrain, and Thomas C. Walters (2010). The Perception of Family and Register in Musical Tones. In Mari Riess Jones, Richard R. Fay, and Arthur N. Popper. Music Perception. Springer. pp. 37–38. ISBN 978-1-4419-6113-6. ^ Jump up to: a b c Hartmann, William Morris (1997). Signals, Sound, and Sensation. Springer. pp. 145, 284, 287. ISBN 1-56396-283-7. ^ Jump up to: a b c Plack, Christopher J.; Andrew J. Oxenham, Richard R. Fay, eds. (2005). Pitch: Neural Coding and Perception. Springer. ISBN 0-387-23472-1. Jump up ^ Robert A. Dobie and Susan B. Van Hemel (2005). Hearing loss: determining eligibility for Social Security benefits. National Academies Press. pp. 50–51. ISBN 978-0-309-09296-8. ^ Jump up to: a b E. Bruce Goldstein (2001). Blackwell handbook of perception (4th ed.). Wiley-Blackwell. p. 381. ISBN 978-0-631-20683-5. ^ Jump up to: a b Richard Lyon and Shihab Shamma (1996). Auditory Representation of Timbre and Pitch. In Harold L. Hawkins and Teresa A. McMullen. Auditory Computation. Springer. pp. 221–223. ISBN 978-0-387-97843-7. ^ Jump up to: a b aruffo/eartraining/research/articles/pratt30.htm Carroll C. Pratt, Journal of Experimental Psychology, 13, 278-85, 1930 Jump up ^ Schwartz, D.A.; Purves, D. (May 2004). Pitch is determined by naturally occurring periodic sounds. Hearing Research 194: 31–46. doi:10.1016/j.heares.2004.01.019. Retrieved 4 September 2012. ^ Jump up to: a b c d Olson, Harry F. (1967). Music, Physics and Engineering. Dover Publications. pp. 171, 248–251. ISBN 0-486-21769-8. Jump up ^ Cariani, P.A.; Delgutte, B. (September 1996). Neural Correlates of the Pitch of Complex Tones. I. Pitch and Pitch Salience. Journal of Neurophysiology 76 (3): 1698–1716. PMID 8890286. Retrieved 13 November 2012. Jump up ^ de Cheveigné, A.; Pressnitzer, D. (June 2006). The case of the missing delay lines: Synthetic delays obtained by cross-channel phase interaction. Journal of the Acoustical Society of America 119 (6): 3908–3918. Bibcode:2006ASAJ..119.3908D. doi:10.1121/1.2195291. PMID 16838534. Retrieved 13 November 2012. Jump up ^ Kaernbach, C.; Demany, L. (October 1998). Psychophysical evidence against the autocorrelation theory of auditory temporal processing. Journal of the Acoustical Society of America 104 (4): 2298–2306. Bibcode:1998ASAJ..104.2298K. doi:10.1121/1.423742. PMID 10491694. ^ Jump up to: a b Pressnitzer, D.; de Cheveigné, A., Winter, I.M. (January 2002). Perceptual pitch shift for sounds with similar waveform autocorrelation. Acoustics Research Letters Online 3 (1): 1–6. doi:10.1121/1.1416671. Jump up ^ Burns, E.M.; Viemeister, N.F. (October 1976). Nonspectral pitch. Journal of the Acoustical Society of America 60 (4): 863–869. Bibcode:1976ASAJ...60..863B. doi:10.1121/1.381166. Jump up ^ Fitzgerald, M.B.; Wright, B. (December 2005). A perceptual learning investigation of the pitch elicited by amplitude-modulated noise. Journal of the Acoustical Society of America 118 (6): 3794–3803. Bibcode:2005ASAJ..118.3794F. doi:10.1121/1.2074687. PMID 16419824. Jump up ^ B. Kollmeier, T. Brand, and B. Meyer (2008). Perception of Speech and Sound. In Jacob Benesty, M. Mohan Sondhi, Yiteng Huang. Springer handbook of speech processing. Springer. p. 65. ISBN 978-3-540-49125-5. Jump up ^ Levitin, Daniel (2007). This is Your Brain on Music. New York: Penguin Group. p. 40. ISBN 0-452-28852-5. The one with the slowest vibration rate—the one lowest in pitch—is referred to as the fundamental frequency, and the others are collectively called overtones. Jump up ^ Sachs, C. and Kunst, J. (1962). In The wellsprings of music, ed. Kunst, J. The Hague: Marinus Nijhoff. Cited in Burns (1999). Jump up ^ Malm, W.P. (1967). Music Cultures of the Pacific, the Near East, and Asia. Englewood Cliffs, NJ: Prentice-Hall. Cited in Burns (1999). Jump up ^ Burns, Edward M. (1999). Intervals, Scales, and Tuning, The Psychology of Music second edition. Deutsch, Diana, ed. San Diego: Academic Press. ISBN 0-12-213564-4. Further reading[edit] Moore, B.C. & Glasberg, B.R. (1986) Thresholds for hearing mistuned partials. as separate tones in harmonic complexes. J. Acoust. Soc. Am., 80, 479–483. Parncutt, R. (1989). Harmony: A psychoacoustical approach. Berlin: Springer-Verlag, 1989. Plack, Christopher J.; Andrew J. Oxenham, Richard R. Fay, eds. (2005). Pitch: Neural Coding and Perception. Springer. ISBN 0-387-23472-1. Schneider, P.; Sluming, V.; Roberts, N.; Scherg, M.; Goebel, R.; Specht, H.-J.; Dosch, H.G.; Bleeck, S.; Stippich, C.; Rupp, A. (2005): Structural and functional asymmetry of lateral Heschls gyrus reflects pitch perception preference. Nat. Neurosci. 8, 1241-1247. Terhardt, E., Stoll, G. and Seewann, M. (1982). Algorithm for extraction of pitch and pitch salience from complex tonal signals. Journal of the Acoustical Society of America, 71, 679-688. External links[edit] Wikimedia Commons has media related to Pitch (music). 12 Tone Equal Temperament Frequency Table Maker Online Guide to Pitch and Clefs [show] v t e Melody [show] v t e Musical notation [show] v t e Harmony [show] v t e Timbre Categories: Pitch (music)PerceptionAuditory perceptionPsychoacousticsCognitive musicology Navigation menu Create accountLog inArticleTalkReadEditView history Main page Contents Featured content Current events Random article Donate to Wikipedia Wikimedia Shop Interaction Help About Wikipedia Community portal Recent changes Contact page Tools What links here Related changes Upload file Special pages Permanent link Page information Data item Cite this page Print/export Create a book Download as PDF Printable version Languages العربية Català Deutsch Eesti Español Esperanto فارسی Français Gaeilge 한국어 Bahasa Indonesia Italiano Magyar Bahasa Melayu Nederlands 日本語 Norsk nynorsk Polski Português Русский Simple English Slovenčina Svenska Türkçe Українська Tiếng Việt 中文 Edit links This page was last modified on 2 July 2014 at 07:44. 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