Anechoic chamber: How loud can you shout?

How loud is a scream?
When a person screams, sound waves are created - i.e. audible vibrations in the air. Specialised measuring devices, such as a sound level meter, can be used to determine exactly how loud a scream is. To ensure that no other noises distort the results, such measurements are often carried out in special rooms. These are called anechoic rooms - they are built in such a way that the walls, floor and ceiling do not reflect any sound. This means that even a single scream can be recorded very accurately and the volume can be represented as a numerical value.