baud (bôd, bōd) [key], measure of the rate at which signals are transmitted over a telecommunications link. It is equivalent to the number of elements or pulses transmitted in one second, e.g., in computer input/output, 2400 baud equals 2400 bits per second (bps) if each pulse encodes one bit (either 0 or 1). Many modems permit the encoding of several bits per baud. A 9600-bps modem that operates at 2400 baud sends four bits per baud by using a range of 16 tones (representing the four-bit combinations 0000 to 1111) to transmit data, and data compression can boost the effective transmission rate even higher. Because of this, the data transfer rate of a modem is measured in bits per second.