For the Pentecostal street preachers, turning up the volume was the means by which they proselytized the community. In this instance, it wasn’t the content of the religious speech that was most important. The services were conducted in Spanish, but most of the youth targeted by the church members spoke only English. Nonetheless, the church’s occupation of the sonic landscape (sonicscape?) for a few hours on a summer evening symbolized to many the presence of God.
Read it all here.
Roman Catholic street missionaries in the 1930s and 1940s pursued the same agenda. They'd roll into a small southern or midwestern town, unpack the trailer chapel (seen, of all places, in Lilies of the Field starring Sidney Poitier), hook up their speakers, and start the Mass. Sometimes they'd make converts, other times they'd have water balloons thrown at them. Read about that phenomenon in American Catholic life here. Weiner, Krueger, and Remillard recognize this trope in so many other places. A good blog read and what looks like a great book, too.
One of the best Lilies scenes, of course, occurs when Homer Smith (Poitier) trains the exiled German nuns in the "Amen" chorus. That's not Poitier singing, but rather composer Jester Hairston's voice. Hairston arranged traditional African-American spirituals for several other Hollywood productions. Here's your sound of religion at work. That scene appeared in 1964; within a decade suburban white parishes across the nation had appropriated it for youth choruses. Remillard and company are onto something perhaps more elemental, which the motor missions priests understood, too. Sometimes increased volume helps spread the message. Let those with ears....