## A Musical Time-Varying Filter Example

Note, however, that a gain may vary with time *independently*
of to yield a linear *time-varying* filter. In this case,
linearity may be demonstrated by verifying

*tremolo*function, which can be written as a time-varying gain, . For example, would give a maximally deep tremolo with 4 swells per second.

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Analysis of Nonlinear Filters

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Nonlinear Filter Example: Dynamic Range Compression