Sound & Hearing

Tone Memory

This exhibit demonstrates the surprising difficulty of remembering and matching a musical note. The visitor is provided with a reference tone as well as a second tone which can be adjusted with the use of a knob. The challenge is to hear the reference tone and then match the frequencies of the two tones based on the memory of that first tone. When listening to the tones together, one can hear fluctuations in loudness called beats. The greater the number of beats per second the farther apart the two tones are in frequency. These beats help musicians tune their instruments by enabling them to detect tiny differences in pitch by ear and make the appropriate adjustments.