In practical terms, these compression rates make possible radio broadcasting of CD-quality music. All three layers are defined for both monaural and stereo sound. Definitions for surround sound and other high fidelity applications are under consideration. The number of simultaneous instruments a synthesiser can play. Obstructions Even when sounds originate in the same room, they are often obstructed by objects like furniture before they reach a person's ears.
Occlusions Sounds that originate from a sound source behind a wall or door or other solitary object.
In so doing, they are subtly altered - usually with a volume drop and muffling, depending on the material and thickness of the obstruction. A revolutionary method for generating sound. This technique emulates the impulse patterns of real-world instruments using a software model. Polyphony The number of voices a synthesiser can play at any one time. The study of how the human brain perceives sound.