A Coveted Ability
Physics of Music
Absolute pitch, otherwise known as AP, is a person's ability to identify and produce a given pitch. This is done without the use of a reference tone. Pitch is determined by the number of vibrations per second. There are two types of AP. Passive pitch is when a person can identify the name of the note that is played and active pitch is when a person can sing a named note. Absolute pitch possessors can name a note and denote if the note is sharp or flat. This ability is only displayed in only a small percent of people. It is said that less than one in ten thousand people in the United States possess AP. However, not only humans possess this ability. Songbirds and wolves have demonstrated absolute pitch. (http://www.biography.ms/Perfect_pitch.html) The components which influence the acquisition of AP in humans is debated and is a topic of recent study.
Background in Music
The University of California San Francisco performed research on what causes this ability. One factor they found was the age at which the person had first formal musical training. The number of people who had AP was significantly more if they began learning music from the ages of four to six. A graph of this analysis is shown in figure 1. (Baharloo)
Figure 1. Background in Music
In addition to a background in music, people who have AP are four times more likely to have other members of their family with AP than people who don't have AP. This suggests that genetics play a role in the formation of absolute pitch. In figure 2, you will see the family pedigree of some of some of members who were tested for AP by the University of California San Francisco. Also, they found that a sibling, who has early musical training, of a AP possessor is 15 times more likely to have AP than a person with early musical exposure but who has no family members with absolute pitch. (Baharloo)
Figure 2. Family Pedigrees
In a study conducted by the University of California San Diego, they found that people who speak Mandarin or Vietnamese had a significantly higher chance of possessing AP. Since both of these languages are tone languages, recognizing pitch is essentially for conveying and understanding meanings of words. This suggests that the ability to acquire AP is universal. The study tested seven native speakers of Vietnamese and gave them a list of ten Vietnamese words to read outloud. The computer recorded each of their responses and calculated the differences of the average pitches among the subjects. The average pitch difference was less than 1.1 semitone. More than half of the subjects had pitch differences of less than .5 of a semitone. These subjects possess AP. In the second study they compared 15 Mandarin speakers. They compared their responses between the two days to see the differences of the average pitch they produce. The results are seen in Table 1.
Table 1. Pitch Differences
1st reading: Day 1 vs. 25440 11
2nd reading: Day1 vs. 25 53110
1st vs. 2nd reading: Day 1 553110
1st vs. 2nd readin: Day 2643110
More than half of the Mandarin speakers had a pitch difference of less than .5 semitone. The results were not affected by different days they were tested or by being tested twice in succession. This shows the high degree of absolute pitch tendicies among Mandarin speakers. Vietnamese and Mandarin speakers show a high percentage of AP and to a very fine percision even without any musical training. The development of AP among these people were from the early acquisition of tonal language.(Deutsch)
A study done by Harvard medical school suggests another influence on the acquisition of AP. In their study, they tested blind musicians of an average age of 47. All their...