Pitches are the musical ingredients used for cooking up a good melody. Scientists have long known that pitch is important, not just for perceiving music but also for understanding speech and hearing in noisy environments. But we are still debating how the brain encodes pitch. Neuroimaging studies show activation of the auditory cortex when pitches are presented to adults, so that region of the brain would appear to be involved in pitch processing. Babies do not have a fully developed auditory cortex, but our group’s work at the University of Washington shows that they can nonetheless perceive pitch.
When an instrument plays a note, it produces a complex sound wave made up of multiple harmonics. The lowest harmonic, or fundamental frequency, carries the pitch, and the harmonic composition determines the note’s timbre. Timbre is the quality that makes a trumpet sound different from a violin.
In our most recent experiment,...
