Vibrato - Acoustic Basis

Acoustic Basis

The use of vibrato is intended to add warmth to a note. In the case of many string instruments the sound emitted is strongly directional, particularly at high frequencies, and the slight variations in pitch typical of vibrato playing can cause large changes in the directional patterns of the radiated sound. This can add a shimmer to the sound; with a well-made instrument it may also help a solo player to be heard more clearly when playing with a large orchestra.

This directional effect is intended to interact with the room acoustics to add interest to the sound, in much the same way as an acoustic guitarist may swing the box around on a final sustain, or the rotating baffle of a Leslie speaker will spin the sound around the room.