Digital Audio
In the realm of digital audio, a signal processor is a device that modifies an audio signal, either analog or digital. It can be a piece of electronic hardware or computer software. A basic example of a signal processor is a high-pass filter, which removes low frequencies from a signal.
Traditionally, signal processors were electronic circuits that affected analog signals. In digital audio, signal processors can be software that alters digitized audio information. The term digital signal processing (DSP) usually refers to the processors that are involved in calculating the effect a digital signal processor will have on an audio data stream. For example, HD Accel cards by Digidesign contain processors that calculate the changes to a digital audio signal.
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