Digital Signal Processing - a category of techniques that analyze signals from sources such as sound, weather satellites and earthquake monitors. Signals are converted into digital data and analyzed using various algorithms such as Fast Fourier Transform. Once a signal has been reduced to numbers, its components can be isolated, analyzed and rearranged more easily than in analog form. DSP is used in many fields including biomedicine, sonar, radar, seismology, speech and music processing, imaging and communications. DSP chips are used in sound cards for recording and playback, compressing and decompressing and speech synthesis. Other audio uses are in amplifiers that simulate concert halls and surround sound effects for music and home theater.