Experts at the university's Eastman School of Music and Department of Brain and Cognitive Sciences have revealed that their new test is based on a technique to discern how infants recognize words in a language they are learning.
"Tests for perfect pitch have always demanded that subjects already have some musical training or at least familiarity with a particular piece of music, which really limits the pool of candidates you can test," said Elizabeth Marvin, professor of music theory at the world-renowned Eastman School of Music at the University of Rochester.
"That means nobody really knew how prevalent perfect pitch is in humans in general," she added.
While making a presentation at the International Conference on Music Perception and Cognition in Sapporo, Japan, recently, the researchers revealed that they began their study by looking into research on pitch perception in animals and found that perfect pitch was widespread in the animal kingdom, even though it's very rare in humans.
Previous studies had shown that animals such as birds, for instance, can identify a series of repeated notes with ease, but when the notes are transposed up or down even a small amount, the melody becomes completely foreign to the bird.
This holds true for almost all animals, but not humans, which suggests that, ironically, common relative pitch hearing may require more brainpower than perfect pitch.
With a view to determining the cognitive basis for perfect pitch, Marvin and her colleague Elissa Newport wanted to test the basis for pitch perception and memory in people who had never been musically trained in order to get a better idea of exactly how common perfect pitch is in humans.
During the study, both musicians and non-musicians listened to groups of three notes, with the groups played in a continuous stream in random order for 20 minutes.
The researchers observed that just like the human mind quickly begins to identify new sound sequences (words) in a foreign language, the students learned to identify the groups of notes embedded in the stream, though they could not identify and remember the names of particular notes as they were constantly coming in the 20-minute stream.
Marvin and Newport then tested the students by replaying the note groups, as well as new groups that the students had not heard before. The students were then asked whether each group of notes was familiar or unfamiliar.
Some of the original note groups had been transposed to a different key without the knowledge of the students.
Students who unconsciously used perfect pitch to identify notes stumbled over the transpositions, and heard them as a new group of notes they had never heard before.
On the other hand, students who relied on relative pitch heard the transposed notes and automatically and unconsciously recognized them as familiar, the notes seemed to be of the same group heard before.
Marvin and Newport says that, surprisingly, there were a number of non-musicians who used perfect pitch to identify groups of notes, but did not know they had perfect pitch.
The team is now investigating the other cognitive abilities of this new group of listeners with perfect pitch, to determine what might distinguish them from the more numerous listeners with only relative pitch perception.
They are also planning to investigate a controversial hypothesis that native speakers of tonal languages like Chinese, which utilize pitch to distinguish different words, have their perfect pitch abilities enhanced by their language's necessary attention to pitch.