Direct-Stream Digital (DSD) is a technology to store audio signals on digital storage media and is used for the super audio compact disc (SACD). The signal is stored as sequence of single bit values at a very high frequency sampling rate of approximately 2.8224 MHz. Noise shaping and oversampling are used to reduce distortion caused by the very high quantization of the audio signal to a single bit. Due to the high sampling rate the bandwidth and therefore the audio quality can be higher than what is possible with the 44.1kHz PCM format used for normal audio CDs.