| A | B |
|---|
| absorption | the process by which radiant energy is taken in and transformed into other forms of energy. |
| acoustics | the study sound |
| chord | three or more notes sounded together together chosen by the rules of harmony (otherwise it's a discord.) |
| concave lens | lens that curves inward in the center and is thicker at the edges. |
| convex lens | lens that is thicker in the center than at the edges. |
| decibel | a unit of measurement for the loudness of sound; abbreviation dB. |
| echo | sound that is reflected by an object. |
| electromagnetic spectrum | the entire range of radiation extending in frequency approximately from 10^23 to 0 cycles per second, this includes rays, ultraviolent radiation, visible light, infared rays, microwaves radio waves, heat, and electric current. |
| frequency | number ofvibrations pper unit of time also the number of waves passing a point per unit of time. |
| hertz | unit for measurement frequency, equal to one cycle per second; abbreviation Hz. |
