Reflectogram

A reflectogram is also called an echogram or impulse response of a room , from the Latin reflectere = to bend back. The reflectogram is a record of the sound pressure as a function of time after the sound excitation of a room by a pulse process , e.g. B. a pistol shot from a blank gun .

Due to the room delimitation surfaces and the furnishings in a room, there are more or less large sound reflections depending on the size of the sound absorption coefficient of these boundary surfaces . In a closed room, the listener receives, in addition to the portion coming directly from the sound source (sound transmitter) as direct sound, other sound components that originate from reflections at the boundary surfaces as room sound , whereby these reflections can take place once or several times. The reflected sound components arrive at the measuring point with a time delay compared to the direct sound, because they have to cover a longer distance.

If these successively arriving sound pressure components are recorded by a recording device with high temporal resolution, a reflectogram is obtained.

Such reflectograms can be used to estimate which reflections contribute to improving audibility and which are to be regarded as harmful.