Filtering removes unwanted frequency bands using high-pass, low-pass, and notch strategies

Evidence

One of the simplest forms of electronic signal processing is to filter the signal in order to remove unwanted components. For example, often low-­frequency noises, such as ventilation and traffic rumble, need to be removed from the signal picked up by the microphone. A high-pass fil­ ter would accomplish this and mixing desks often provide some form of high-pass ­filtering for this reason. High frequencies also often need to be removed to either ameliorate the effects of noise and distortion or remove the high-frequency components that would cause alias distortion in digital systems. This is achieved via the use of a low-pass filter. A third type of fil­ ter is the notch filter, which is often used to remove tonal interference from signals. — David Howard, Jamie Angus, coustics and Psychoacoustics, 2389

Categorization

• DEFINE: Taxonomy of the three basic filter types — high-pass, low-pass, notch — with their everyday acoustic targets: rumble, hiss/aliasing, and tonal interference.