FIR filters
Christopher Bennett · Focal Press eBooks · 2020
Feed-forward, or finite impulse response (FIR) filters, use the instantaneous input as well as previous inputs. The output of an FIR filter can be determined with the convolution algorithm. FIR filters have specific artifacts relating to their phase response, which are discussed specifically with regard to audio and music. A similar algorithm, correlation, can be used to estimate lag between two audio signals or to find sounds within a signal, known as matched filtering. Mathematical and programming examples are provided for each of these concepts, including vocal processing code for adding reverb to a recording using the convolution algorithm. The chapter concludes with a project for coding first-order low-pass and high-pass FIR filters.