tags: music mus-407 noise-gate noise gate production compression dynamics drp dynamic-range-processing

Noise Gate

A noise gate (or simply gate) is a type of [DRP] that acts as a switch that opens/closes depending on whether [signal] level is above/below an [amplitude] [threshold]

• when signal $>$ threshold, the gate is "open" and allows signal to pass through
• when signal level $\leq$ threshold, the gate is "closed" silencing the signal

Gates are commonly used for removing low-level background [noise] and outright removing the [noise floor].

• assumed that noise level is below signal level
• for basic gates, not possible to remove noise while signal is present
• works best when signal masks noise
• works better on short [transient]s (percussion, drums, staccato) than sustained or long-decay sounds (held notes)

Basic noise gates only check amplitude; however, more advanced noise gates have additional features for more flexibility/utility:

• use [spectral analysis] or [frequency] tracking to remove noise from all parts of the signal, not just through amplitude thresholds
• allow for specific amount of [decibel] reduction, rather than just muting the signal
• allow for an [envelope] for the gate: specific attack/release times on signal

Workflow

• Determine approximate threshold
  • ex. loop through part of sample with noise and check what the general threshold is
• Play sample and adjust threshold so that noise is removed as much as possible

Sources

• MUS 407 Dynamic Range Processing