Image shift
- Sound dislocated from its correct position, to be more left and / or right of center.

Hertz
- The measuring unit of frequency or the speed of vibration of a sound wave. Synonymous with “cycles per second” (CPS).

Helmholtz resonator - A reactive, tuned, sound absorber. A bottle is such a resonator. It can employ a perforated cover or slats over a cavity. An acoustic guitar or violin body is a Helmholtz resonator.

Haas effect - Also called the precedence effect. Delayed sounds are integrated if they fall on the ear within 20 to 40 msec of the direct sound. The level of the delayed components contributes to the apparent level of the sound.

Grazing Effect - The way in which sound is absorbed by the audience; stepping or raking the seating reduces the absorption, and improves sight lines.

Grating, reflection phase - An acoustical diffraction grating to produce diffusion of sound

Grating, diffraction

GoBo - A freestanding device used to inhibit the propagation of sound waves. Gobos are usually employed to prevent microphone leakage between two instruments being recorded simultaneously. Typically a set of portable dividers covered with acoustical treatments.

Fundamental - The basic pitch of a musical note.

Front-to-back imaging - The placement of vocal or musical information ahead of (closer to) or behind (farther from) center position, front-to-back.