- That portion of a sound wave which bounces off a surface and reverses direction.
- If the sound takes more than 90 milliseconds to travel via the relected path compared to the direct path it will be perceived as an echo if it is not substantially attenuated.
- Reflections come from walls, floor and ceiling
- Direct sound reaches the listener's ears first
- Direct sound localizes the source of the sound
- Early reflected sound arrives after the direct sound
- Early reflections are needed to give the feeling that someone is present at a space
- Reverberation arrives from every direction (as a result of complex reflections)
- Reverberation creates the sense that performance is taking place in a large space.
- The three variables descriptive of a reflection:
- angle of incidence = angle of reflection
- Early Reflections:
- Single-bounce reflections from front and side walls, ceiling and floor
- Level rarely more than 10 dB below the direct
- Delay from 1 to 20ms - obviously this time delay is dependent on the distance from the nearest wall or reflecting object, but within this time frame the reflection will not be perceived as an echo.
Subjects: Noise & Vibration