Kevin Dooley - kdooley@ucsd.edu
Department of Psychology
University of California, San Diego
La Jolla, CA 92093
Popular version of paper 2pMUa4
Presented Tuesday afternoon, November 1, 2011
162nd ASA Meeting, San Diego, Calif.
Absolute pitch, also known as perfect pitch, is the ability to name or produce the pitch of a tone without an external reference. It is quite a rare phenomenon as formally defined, with absolute pitch possessors estimated at less than 1 in 10,000 in Western populations, and is associated with enhanced performance on some musical tasks.
However, previous research suggests that most people may have some access to absolute pitch information, particularly when tests involve familiar musical material and do not require the use of learned pitch labels such as “C#”. For example, in one study that asked participants to recall and reproduce popular songs, the majority of subjects came closer than chance to the correct pitch of the original recordings (Levitin, 1994). This raises the question of whether long-term memory for familiar sounds is truly widespread throughout the population, or whether absolute pitch possessors have an advantage over non-possessors in such tasks.
To test this, 36 trained musicians--18 absolute pitch possessors, and 18 non-possessors with equivalent age of onset and length of musical training-- were asked to recall a song of their choosing that they could easily imagine, and then to sing, hum, or whistle a few seconds of the song in the same key in which it was “heard”. Subjects then repeated this procedure with their cell phone ringtone. All responses were recorded, and then a recording of the original song and ringtone was obtained for comparison.
Subjects were free to choose any song they wished given the condition that it must exist as a specific recording whose title and artist they could identify (as opposed to a song like “Happy Birthday” which may have been listened to in multiple keys). Furthermore, subjects were not allowed to choose a song or ringtone if they already knew what key it was in based on pre-existing knowledge (such as by recalling the sheet music or having previously checked their ringtones against a piano). Subjects were not told in advance that they would be asked to recall or make judgments about songs or ringtones.
Figure 1: The differences (in semitones) between the pitch class of each subject’s response (vocalized pitch) compared to that of the actual recording (target pitch). (a) AP possessors, song (n = 18). (b) AP non-possessors, song (n = 18). (c) AP possessors, ringtone (n = 18). (d) AP non-possessors, ringtone (n = 18).
Responses were recorded and compared to the corresponding pitches of the original song recordings and cell phone ringtones using pitch analysis software. Figure 1 shows the differences between the pitch class of each subject’s responses (vocalized pitch) compared to that of the actual recordings (target pitch). Note that random guessing (chance performance) would appear roughly equally spread out across all 12 pitch classes for any given target tone. Given a song or ringtone starting on C, for example, random guessing should yield a correct response of C 8.33% of the time (1 out of 12) or, more broadly, a tone that is no more than one semitone (the distance between two adjacent notes on a piano) higher or lower than the correct tone (in this case, a response of B, C, or C#) 25% of the time. In contrast, above-chance performance would appear as a larger-than-expected number of responses falling close to the target tone (lots of subjects landing on, or near, 0 difference between vocalized and target pitch, in the middle of the graph).
Figure 2: Percentage of subject responses in each group that were within one semitone of the correct pitch for each task, (chance performance ≈ 25%).
As can be seen in Figure 2, both groups performed significantly better than chance on the popular songs. Specifically, 33% of the subjects with absolute pitch produced the correct pitch and 78% came within 1 semitone of the correct pitch. In comparison, 33% of subjects without absolute pitch produced the correct pitch and 56% came within 1 semitone.
However, the two groups’ performances on their cell phone ringtones were substantially different. While absolute pitch possessors were once again significantly more accurate than chance, with 50% producing the correct pitch and 78% within 1 semitone, the performance of non-possessors was no better than chance, with none (0%) producing the correct pitch and only 22% within 1 semitone (in the latter case, random guessing would yield a 25% accuracy rate on average).
At present, it is unclear why both groups demonstrated better-than-chance accuracy when reproducing the pitch of popular songs, but only the absolute pitch possessors did so for cell phone ringtones. It is worth noting that many of the ringtones that subjects chose actually were excerpts from popular songs, suggesting that it was the context, rather than the content, that mattered most. Thus, one possible explanation is that people with absolute pitch can remember and reproduce absolute pitch information even without consciously focusing on the sounds they hear, whereas those without absolute pitch can do so only in musical contexts that promote actively listening to and engaging with the sounds in a meaningful way. So, while subjects may have sung along with their favorite tunes on occasion, they would not, in all likelihood, have practiced singing along with their cell phones.
In conclusion, these findings support the existence of widespread long-term pitch memory for familiar musical sounds but also point to an advantage for absolute pitch possessors under some circumstances, even when pitch labels are not required. More research is needed to determine exactly how this advantage is achieved and in which situations it is most apparent.
Sound demonstration 1
Sound demonstration 2
#1: absolute pitch possessor, song vocalization
#2: absolute pitch possessor, corresponding song (link to actual recording)
Sound demonstration 3
Sound demonstration 4
#3: non-possessor, song vocalization
#4: non-possessor, corresponding song (link to actual recording)
Sound demonstration 5
Sound demonstration 6
#5: absolute pitch possessor, ringtone vocalization
#6: absolute pitch possessor, corresponding ringtone (actual recording)
Sound demonstration 7
Sound demonstration 8
#7: non-possessor, ringtone vocalization
#8: non-possessor, corresponding ringtone (actual recording)