We live in an age of sub­ti­tles. On some lev­el this is a vin­di­ca­tion of the cinephiles who spent so much of the twen­ti­eth cen­tu­ry com­plain­ing about shod­dy dub­bing of for­eign films and pub­lic unwill­ing­ness to “read movies.” Today we think noth­ing of read­ing not just movies but tele­vi­sion shows as well, even those per­formed in our native lan­guage. For an increas­ing pro­por­tion of at-home view­ers — includ­ing on-com­put­er, on-tablet, and on-phone view­ers — sub­ti­tles have come to feel like a neces­si­ty, even in the absence of any hear­ing dif­fi­cul­ties. Vox’s Edward Vega inves­ti­gates why this has hap­pened in the video above.

The chief irony of the sto­ry is that the intel­li­gi­bil­i­ty of film and tele­vi­sion dia­logue seems to have degrad­ed as a result of sound record­ing and edit­ing tech­nol­o­gy hav­ing improved. Back in the ear­ly days of sound film, actors had prac­ti­cal­ly to shout into bulky micro­phones con­cealed on-set or placed just off it. Today, a pro­duc­tion can keep a cou­ple of boom mics sus­pend­ed over­head at all times, but also rig each actor up with a few hid­den lava­liers. The upshot is that dia­logue almost always gets record­ed accept­ably, but it removes the pres­sure on per­form­ers to deliv­er their lines with the clar­i­ty they would, say, on stage.

For bet­ter or for worse, this has encour­aged a ten­den­cy toward unprece­dent­ed­ly nat­u­ral­is­tic dia­logue, man­i­fest though it often does as slur­ring and mum­bling. At the same time, says dia­logue edi­tor Austin Olivia Kendrick, film­mak­ers have come to believe that “if you want your movie to feel ‘cin­e­mat­ic,’ you have to have wall-to-wall bom­bas­tic, loud sound.” Yet a sound­track can be cranked up only so high, an explo­sion of the same loud­ness as a human voice won’t sound like an explo­sion at all: “you need that con­trast in vol­ume in order to give your ear a sense of scale.”

This need to pre­serve the sound mix’s “dynam­ic range” — just the oppo­site of the “loud­ness wars” in pop­u­lar music — thus keeps dia­logue on the qui­et side. You can still hear it clear as day in a the­ater equipped with up-to-date sur­round-sound facil­i­ties, but much less so when it’s com­ing out of the tiny speak­ers crammed into the back of a flat-pan­el tele­vi­sion, let alone the bot­tom of a cell­phone. Turn­ing the sub­ti­tles on and leav­ing them on has emerged as a com­mon solu­tion to this thor­ough­ly mod­ern prob­lem. Anoth­er would be to invest in a prop­er high-end ampli­fi­er and speak­er set­up, which, if wide­ly adopt­ed, would cer­tain­ly come as a vin­di­ca­tion for all the frus­trat­ed audio­philes out there.

Relat­ed con­tent:

Why Do Peo­ple Talk Fun­ny in Old Movies?, or The Ori­gin of the Mid-Atlantic Accent

Why Mar­vel and Oth­er Hol­ly­wood Films Have Such Bland Music: Every Frame a Paint­ing Explains the Per­ils of the “Temp Score”

How the Sounds You Hear in Movies Are Real­ly Made: Dis­cov­er the Mag­ic of “Foley Artists”

The Dis­tor­tion of Sound: A Short Film on How We’ve Cre­at­ed “a McDonald’s Gen­er­a­tion of Music Con­sumers”

David Lynch on iPhone

Based in Seoul, Col­in Marshall writes and broad­casts on cities, lan­guage, and cul­ture. His projects include the Sub­stack newslet­ter Books on Cities, the book The State­less City: a Walk through 21st-Cen­tu­ry Los Ange­les and the video series The City in Cin­e­ma. Fol­low him on Twit­ter at @colinmarshall or on Face­book.