Editing Dynamic range compression (section)

{{Short description|Audio signal processing operation}}
{{About|a process that intentionally reduces the dynamic range of audio signals|similar reductions caused by circuit imperfections|Gain compression|processes that reduce the size of digital audio files|Data compression{{!}}Audio compression (data)}}
{{Use American English|date=June 2020}}

[[File:Comp. rack (Supernatural).jpg|thumb|150px|A rack of audio compressors in a recording studio. From top to bottom: Retro Instruments/Gates STA level; Spectra Sonic 610; [[Dbx (noise reduction)|Dbx]] 162; Dbx 165; [[Empirical Labs Distressor]]; Smart Research C2; Chandler Limited TG1; Daking FET (91579); and [[Altec Lansing|Altec]] 436c.]]

'''Dynamic range compression''' ('''DRC''') or simply '''compression'''  is an [[audio signal processing]] operation that reduces the volume of loud [[sound]]s or amplifies quiet sounds, thus reducing or ''compressing'' an [[audio signal]]'s [[dynamic range]]. Compression is commonly used in [[sound recording and reproduction]], [[broadcasting]],<ref name="Follansbee">{{Cite book |url=https://books.google.com/books?id=gEN1GbEgb5AC |title=Hands-on Guide to Streaming Media: An Introduction to Delivering On-Demand Media |last=Follansbee |first=Joe |publisher=Focal Press |year=2006 |isbn=9780240808635 |edition=1 |page=84 |oclc=1003326401 |via=Google Books}}</ref> [[sound reinforcement system|live sound reinforcement]] and some [[instrument amplifier]]s.

A dedicated electronic hardware unit or audio software that applies compression is called a '''compressor'''. In the 2000s, compressors became available as software plugins that run in [[digital audio workstation]] software. In recorded and live music, compression parameters may be adjusted to change the way they affect sounds. Compression and [[limiting]] are identical in process but different in degree and perceived effect. A limiter is a compressor with a high [[#Ratio|ratio]] and, generally, a short [[#Attack and release|attack time]].

Compression is used to improve performance and clarity in [[public address system]]s, as an [[Effects unit|effect]] and to improve consistency in [[Audio mixing (recorded music)|mixing]] and [[Mastering (audio)|mastering]]. It is used on voice to reduce sibilance and in [[broadcasting]] and [[advertising]] to make an audio program stand out. It is an integral technology in some [[noise reduction]] systems.