For audio to stream over a network, the data rate has to be small and regular. This means that the size of the file devoted to the first second of sound and the second second of sound has to be exactly the same. This is known as the bit rate of the sound.
A typical streaming sound may be 16 kilobits per second (Kbps), or 16 times 1,024 bytes of information. A file with this bit rate can be streamed over a 28.8 modem that gets data at 28.8Kbps. However, a 32Kbps sound cannot stream smoothly.