soundsflushes

Soundsflushes is a term occasionally used in discussions of digital audio to describe a transient artifact that appears as a rapid, brief redistribution of spectral energy—felt as a sudden flush of sound followed by a quick return to baseline. The coinage combines the senses of sound and a flushing action, echoing the abrupt release of energy characteristic of the phenomenon. The term is not widely adopted in peer-reviewed acoustics but is used in informal audio production communities to refer to this class of transient irregularities.

Characteristics of soundsflushes include a short time scale (often tens of milliseconds), a broad or shifting spectral emphasis, and a perceptual flutter or wash across the audio. They may occur with sudden loud transients, aggressive dynamic processing, or dense multi-track material. Listeners might perceive momentary thinning, a swoosh, or an unusual tonal tilt during the event, even when the overall level does not change markedly.

Causes are typically tied to dynamic processing or DSP chaining. Common triggers include hard-knee compression or limiting with fast attack and release, lookahead processing, or extreme loudness normalization. Phase interactions, sample-rate conversions, or aliasing in DSP chains can also contribute. Improper dithering and undersampling can worsen the perceptual impact in some systems.

Detection and mitigation rely on spectral analysis and careful listening. Techniques include using slower or softer attack/release settings, applying multi-band dynamics, and choosing transparent limiters. Ensuring proper gain staging, high-quality sample-rate conversion, and appropriate dithering helps reduce artifacts. Verifying phase coherence between channels and avoiding overly aggressive processing in mastering are also recommended.

In reference works, soundsflushes are described more as a nuisance artifact to minimize than as a deliberate effect, with best practices emphasizing thoughtful DSP design and careful monitoring.