A digital representation of a sound is called a SAMPLE. Sampling a sound is a similar process to recording a movie using film (not video tape). With film, a camera takes 32 frames (pictures) per second and this is enough information to fool the brain into seeing a continuous and uninterrupted motion. With sound, the brain needs much more information. A good SAMPLING RATE is in excess of 8000 frames (samples) per second, that is 8 kilo-Hertz (8 kHz). A better sampling rate is 22 kHz. The best sampling rates are in excess of 44.1 kHz. 44,100 Hz (44.1 kHz) is the standard sampling rate for CD production. At this sampling rate the extremes of sound frequency from the lowest pitches to the highest pitches which the ear is physically capable of hearing can be accurately represented.
Another aspect of sampling is the SAMPLE RESOLUTION of the sample. That is, how accurately an individual sample is stored digitally, for example, 8 bit samples, 16 bit samples, 32 bit samples, etc. The higher the bit resolution, the more accurately the sample is represented digitally. Sixteen bit samples are generally considered high enough resolution to accurately represent an individual sound for the human ear.
An important factor which enters into decisions regarding rate and resolution of sampling is hardware limitations. High sampling rates combined with high resolution rates require large amounts of memory and/or disk storage. If hardware capabilities are limited then certain tradeoffs will have to be considered when deciding on sample rate and resolution. When a sound is sampled by a computer or sampler (digitizer), the resulting waveform can be saved as a computer file called a SOUNDFILE. Some common soundfile formats are AIFF (Audio Interchange File Format), a standard file format supported by applications on the Macintosh and Windows computers; µlaw, an 8-bit sound encoding that offers better dynamic range than standard (linear) 8-bit coding; WAVE (.WAV), a standard sound format for the Windows platform;