Absolute Pitch (AP)
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Absolute Pitch (AP) • A.k.a. ‘perfect pitch’ • The ability to name or produce a tone without a reference tone • Very rare: 1 in 10,000 Vs. Relative pitch (RP) • Most people use relative pitch: • Recognizing tones relative to other tones • Remember and produce intervals abstracted from specific pitch, or given a reference pitch AP: how it works • Thought to be a labeling process: – AP possessors associate names/ meaning with pitches or pitch classes – Retain this association over time • AP is not ‘perfect’; i.e., auditory perception/ pitch discrimination not more accurate than RP Imaging evidence • When making judgments using AP: • possessors compared to non- possessors show more activation in frontal naming/labeling areas • Anatomically, AP possessors show greater planum temporale asymmetry – Apparently due to reduced RH PT size AP ‘flavors’ • AP not purely ‘have’ or ‘have-not; ability level varies along continuum • Some possessors make more accurate judgments with certain instruments – e.g. piano vs. pure sine wave tones – Sometimes called ‘absolute piano’ AP ‘flavors’ cont’d • Other possessors may perform more accurately with white-key notes than black-key notes – E.g. C,D,E vs. C#, D# • May be due to early learning influence – Early musical training on keyboard usually starts with white-key notes only • So, is AP learned? Learnable? Nature vs. Nurture, of course • The debate continues: – Some researchers ascribe genetic origins to AP, suspecting that early musical training is neither sufficient nor necessary – Others find most possessors did have early musical training (age 3-6), suggesting a critical period for development • similar to, and paralleling, language development • Learning AP after this period appears to be difficult to impossible Why don’t we all have AP? • One theory- we’re all born with the potential • but most lose it w/o using it early on – Infants show evidence of AP perception – More prevalent among tone language speakers – General population: can accurately recognize or produce the starting note of popular songs – AP evident in Tritone Paradox perception Absolute Pitch (AP) • AP is a rare and somewhat mysterious ability, occurring in as few as 1 in 10,000 people (according to some reports) • People with AP can sing or identify a note without reference to an external standard • They have memory for the actual pitches in a song, not just the relation between pitches • When people with AP hear a song played in a different key than usual, it sounds wrong to them Pitch is Encoded as a • People with APD eenficnoditie opnitch in a linguistic sense, and process pitch as if it were a semantic concept – Pitch perception activates brain regions involved in associative labeling – Working memory load is reduced when listening to music, because semantic concepts are easier to hold in working memory Benefits of AP • When asked to sing a particular note, people with AP can do so as easily as they can rattle off definitions of words • Reduced working memory may have as- of-yet unknown benefits for processing music, or for simultaneously performing an unrelated task Drawbacks of AP • Semantic representations are stable. When songs are played in the wrong key, the working memory load may increase, since the semantic representations are not consistent with the song • The brain may register a semantic error, which would persist for the entirety of the song (which perhaps results in the unpleasantness reported by people with AP) Why do some people have AP? • Melodies are defined by relative pitch – the relationships between the different notes, not the absolute values of each pitch • AP can be limiting, as some possessors have trouble transposing songs into a new key, because the new key sounds wrong But, then again, why doesn’t everyone? • Cells at several regions of the auditory system encode pitch, so it’s puzzling that this information is not retained in the general population • The psychologist W. Dixon Ward has pointed out that we don’t have to look at a picture of a rainbow to see that a rooster’s comb is red, or sniff a bottle of camphor to identify the smell of a skunk, so why do most people need to run to a piano to identify the pitch of a note? Perhaps everyone does have • People who mighAt nPo…t be classified as "traditional" AP possessors seem to possess abilities resembling AP • Non-AP subjects asked to identify the pitch of a tone do perform better than chance, and their errors approximate a normal distribution around the correct tone • Similar findings were reported for musically trained subjects asked to identify the musical key of a composition Pitch memory vs. pitch labeling • AP consists of two distinct abilities: – The ability to maintain stable, long-term representations of specific pitches in memory, and to access them when required (pitch memory) – The ability to attach meaningful labels to these pitches, such as C# (pitch labeling) • Whereas "true" AP possessors have both abilities, pitch memory might be widespread among ordinary people The challenge… • To come up with an experiment that does not depend on having musical training and the ability to label pitches • Repeated exposure to a song creates a memory representation that should preserve the actual pitches of the song • If one has accurate pitch memory, this should be demonstrated by how well one can remember the key of a well-known song Informal experiment • Ward (1990) informally studied this idea over several months • Whenever a song popped into his head, he sang the song into a tape recorder • He noticed that the keys employed tended to be within a semitone or two of the key in which the song was originally written Dan Levitin’s experiment • In 1994, Levitin investigated whether people have accurate pitch memory • He asked subjects to spontaneously sing the first few notes of songs they knew well • He found that even nonmusicians have fairly accurate memory for pitch • With a different experiment that doesn’t require singing, even higher memory accuracy may be detected Levitin’s Data • These findings provide evidence that some degree of absolute memory representation exists in the general population • To perform accurately on this task, subjects needed to encode pitch information for the songs they have learned, store the information, and recall it without shifting those pitches • Their memory for pitch can thus be characterized as a stable, long-term memory representation Imaging Data • Robert Zatorre and colleagues have looked at the brain areas recruited by AP possessors when perceiving pitch compared to normal subjects • The AP possessors had brain activity in the left posterior dorsolateral frontal cortex, an area that is associated with associative learning (i.e., being able to label things) So, who has AP and why? • Musical training is essential for AP to manifest itself • Without training before a certain age (the upper-limits most likely fall between 9-12 years old), it is essentially impossible to develop true AP • Training, however, can improve performance on pitch labeling Early training is necessary, but not sufficient • Not all people who receive musical training at a young age develop AP • Most musical training emphasizes relative pitch, not absolute pitch • But, sometimes AP develops without explicit note identification training Genetics and AP • There is an association between siblings who demonstrate AP • This may be partially due to shared environment and similar musical training, but cannot be fully explained by these factors • No gene has yet been identified that is associated with AP AAbbssoolluuttee PPiittcchh aanndd TToonnee LLaanngguuaaggee:: TTwwoo NNeeww SSttuuddiieess Diana Deutsch, Jinghong Le, Kevin Dooley, Trevor Henthorn, Jing Shen, and Brian Head Title page F, G, A Background • AP more likely with pitch & verbal label associations formed during critical period? – Enhanced by tone language exposure? (Deutsch, 2002) • Pitch consistency of spoken words across days – Vietnamese & Mandarin > English (Deutsch et al., 2004) • AP evolved to subserve speech (tone acquisition)? • AP prevalence: greater for tone language speakers – Conservatories: Beijing > Eastman (Deutsch et al., 2006) • But: language, ethnicity, or culture/ education? Study 1: AP Prevalence & Tone Fluency • USC Thornton School of Music: 203 students – 110 male, 93 female, mean age = 19.5 – Everyone participated (no self-selection) • Questionnaire – Musical, ethnic, geographic, linguistic background • AP test – 36 notes from 3 octave range, spaced > 1 octave – Kurzweil synth piano samples, CD -> speakers – 3 blocks of 12 + 4 practice notes; no feedback Brief Test of Absolute Pitch Deutsch, Dooley, Henthorn, & Head, J. Acoust. Soc. Am., 2009 USC Fig 1 Study 1: Results • 2 x 4 ANOVA • Age Onset (2-5), (6-9) p = .025 • Group: (tone very fluent), (tone fairly fluent), (tone nonfluent), (nontone) p < .001 2 • Regression: R adj = .54 p < .001 Fluency predicts AP % Deutsch, Dooley, Henthorn, & Head, J. Acoust. Soc. Am., 2009 Study 1: Results continued • Posthoc comparisons • Tone very fluent > each other group p < .001 • Tone fairly fluent > nontone, p = .003 nonfluent, ns trend • Tone nonfluent Vs Nontone: ns, p > .05 Deutsch, Dooley, Henthorn, & Head, J. Acoust. Soc. Am., 2009 Deutsch, Dooley, Henthorn, & Head, J. Acoust. Soc. Am., 2009 USC Fig 2 Deutsch, Dooley, Henthorn, & Head, J. Acoust. Soc. Am., 2009 USC Fig 3 Fig 3 results Deutsch, Dooley, Henthorn, & Head, J. Acoust. Soc. Am., 2009 • 2 x 3 Anova: Age Onset x Group: all n.s. • Post hoc: early vs. late arrivals: n.s. – Late arrivals > Central Conservatory (p = .013) – Early arrivals > Central Conservatory (n.s. trend) Study 2: Pitch Ranges of Speech • Pitch of speech: consistent across subjects within a homogenous linguistic community? – Long term exposure -> mental representation of pitch range of speech? (Deutsch et al., 1992) • Would influence speech perception and production – Pitch range of speech ≈ 1 octave (true across genders, languages, dialects) (cf.