First, it's important to understand what "pitch" means. All sound waves have a wavelength and a frequency. When objects vibrate, they compress the air to make sound waves. The distance between compressions determines a sound wave's wavelength. Frequency is the number of vibrations within a certain amount of time, usually a second. Pitch simply denotes those frequencies within the range of human hearing. The faster the rate of vibration, the higher the pitch; the slower the rate of vibration, the lower the pitch.
Perfect pitch is also known as "absolute pitch." It is the ability to name a musical note by ear.
For example, someone with perfect pitch could hear a single note from a piano and identify it as, say, F-sharp. Or, they could sing a particular note without needing to hear another one first to compare it to. It's a rare ability that may be hereditary.
However, it almost always occurs in those who have had pitch training before the age of six. This has led some researchers to conclude that we are all born with some form of perfect pitch, to help us develop speech. Babies can tell the difference between pitches. After a certain age, that innate ability is lost unless it is developed through musical training.
Some facts about perfect pitch:
- All babies are born with perfect pitch
- 5 percent of autistic people have perfect pitch
- Perfect pitch is more common in blind people
- About one person in 10,000 has perfect pitch
The Acoustical Society of America contributed to the TV portion of this report.