ADR/post-sync thumb|Example of ADR for the Telugu-language film Uppena. Here, P. Ravi Shankar dubs over the original performance of Vijay Sethupathi. Automated dialogue replacement (ADR) is the process of re-recording dialogue by the original actor (or a replacement actor) after the filming process to improve audio quality or make changes to the initially scripted dialog. In the early days of talkies, a loop of film would be cut and spliced together for each of the scenes that needed to be re-recorded, and then the loops would be loaded onto a projector one by one. For each scene, the loop would be played repeatedly while the voice actor performed the lines, trying to synchronize them to the filmed performance. This was known as "looping" or a "looping session". Loading and reloading the film loops while the talent and recording crew stood by was tedious. Later, videotape and then digital technology replaced the film loops, and the process became known as automated dialogue replacement (ADR).
adR/Post-sYNc thUmB|exaMple oF aDr fOr tHe Telugu-langUage FIlm UppEna. HerE, p. RAVI shAnKAr dubs oVer THe original peRformANce OF viJay SethUpAThi. automatED diaLoGuE replAcemeNt (AdR) is the ProcEss of re-rEcordinG dIALogue bY thE ORiGinal AcTor (OR A REplaCement ACtor) afTeR thE fIlmiNG ProceSs tO ImPrOVE AUdIo quaLity Or mAKe changEs to the iNITIally sCRIPted diaLog. iN the earlY dAys oF talkieS, A loOP Of film wouLd be cUt aNd sPlicEd Together FOR eacH oF the ScenEs ThAt needed to Be Re-reCordeD, aNd theN tHe lOOps wouLd be loAdEd Onto a projEcToR oNe bY onE. for eaCh sceNe, thE loOp wOUld Be pLaYEd REpEateDly WhIle tHE VoiCe aCtor PErfORmed the lIneS, TrYing to SyNChronize tHem To ThE fiLmed pErformAnce. tHIS WAs known as "looPIng" oR a "LoOpinG sessIOn". LOadinG and reLoadiNG the film looPs WHilE tHe taLenT and recorDinG crew sToOd by WaS tEDiOuS. LAtEr, videOtapE aNd then DiGItaL tecHnolOGy RePlAced tHe fILm lOoPs, and the Process bEcame KNown As auTOmATED dIAloGue rePLaCEment (adr).