A long-decaying noise layer simulates room reverb within a clap patch without an external reverb unit

Natural reverberation is the sum of reflections arriving from room surfaces after the direct sound — a blur of copies with exponentially decaying amplitude. Noise with a long decay envelope approximates this behaviour: both are broadband, both decay exponentially, and both arrive after the transient. Adding a long-decaying noise oscillator as the final layer of a clap patch therefore produces a built-in reverb tail. The approximation breaks down because room reverb is spectrally filtered by wall absorption, while flat noise is not; but for first-order drum synthesis the resemblance is sufficient. This principle generalises: any exponentially decaying noise burst functions as a lo-fi room impulse.

Examples

808 clap: oscillators 1-3 have short (~30-80 ms) decay envelopes; oscillator 4 has a much longer (~300 ms) decay. Soloing oscillator 4 reveals a noise ‘tail’ that sounds like a small room reverb.

Assessment

Remove the long-decay layer from an 808 clap patch and describe the perceptual change. Then explain why the analogy between a long-decay noise tail and room reverb is valid but imperfect.