A high-pass filter (also known as a bass-cut filter) attenuates signals below a cutoff frequency (the stopband) and allows signals above the cutoff frequency (the passband). The output of this filter is directly proportional to rate of change of the input signal.

High-pass filters are often used to clean up low-frequency noise, remove humming sounds in audio signals, redirect higher frequency signals to appropriate speakers in sound systems, and remove low-frequency trends from time series data thereby highlighting the high-frequency trends.

Common design methods for high-pass FIR-based filters include Kaiser window, least squares, and equiripple. Design methods for IIR-based filters include Butterworth, Chebyshev (Type-I and Type-II), and elliptic.

For more information on filter design, including these methods, see Signal Processing Toolbox™ for use with MATLAB^®. Of particular interest is the built-in filter visualization tool, which you can use to visualize, compare, and analyze different filter responses.