Effective sound library metadata uses four description layers: macro event, meso components, micro timbre, and technical capture info

Freesound recommends a four-layer metadata approach borrowed from professional sound library practice. The macro layer names the whole event (e.g. ‘car crash’). The meso layer breaks the event into distinct audible components (e.g. ‘breaking glass, crushing metal, burning rubber’). The micro layer describes timbral qualities at a synthesis-language level: envelope shape, texture, spatial character (e.g. ‘hard impact, glass shards falling’). The technical layer records capture chain: recorder model, microphone model and type, and any post-processing applied. Together these layers make the sound findable via different search strategies: someone searching ‘metal impact’ or ‘short attack transient’ will find a sound described at the meso and micro levels even if they would never search ‘car crash’. Omitting any layer reduces discoverability.

Examples

Minimal description: ‘car crash’. Well-layered: ‘Car Crash: breaking of glass, crushing metal on metal, burning rubber. Hard impact sounds, glass shards falling to the floor. Recorded with SoundDevices recorder and stereo microphone (Rode NT4), compressed with Waves C4.‘

Assessment

Given the description ‘thunder storm’, rewrite it using all four layers. Identify which layer each new sentence belongs to.