Sound effects but not as you know them
The squelching of a horse walking on mud, rainwater trickling down the gutter. These atmospheric sounds of radio can be hard to create, even with today's technology.
But before it was possible to create and store these familiar sounds digitally, producers and sound engineers had to improvise much further, using wild and wonderful props to create the everyday sounds they wanted.
At the BBC a sound effects room used from the 1920s onwards was full of an eclectic mix of items from bells to brooms used to create the noises that brought radio alive for the population. It was a time when the majority of people didn't have a television, but radios were in almost every household by the 40s.
"It is very easy to underestimate the importance of the sound effects because very often they're going on at an almost subconscious level behind a scene where someone's making a cup of tea," says Andrew Partingon, a studio manager at The Archers. "But take them away and you realise how important they were."
The creation of live sound effects is often referred to as Foley, after the Hollywood sound recordist who pioneered the techniques in the 1920s.
Without it, the clean audio of voices would be a boring world for the listener and Foley devices continue to be used in radio drama today.
In its 1931 Yearbook the BBC said it would be "a great mistake to think of them [sound effects] as analogous to punctuation marks and accents in print". They must be used, the article continued, as "bricks with which to build, treating them as of equal value with speech and music".
When World War Two began, women filled men's roles around the country and the BBC was no different. Elaine Cunningham and Monica Bell were two such women who became "effects girls" and were tasked with producing the sounds to accompany radio that was used to inform and entertain the war-weary public.
By the 1950s, sound effects were a staple part of radio production and programmes from The Goon Show to Schools broadcasts were using the BBC's magical storeroom of audio equipment.
"The inventive, wackiest sound effects work the best, they create realism in a way electronic sounds can't," says Dane Lockland, a sound engineer. "I think the fact that they are still produced in this way today shows how effective they are and I can't imagine audio being produced without somebody in the background walking on a pebble surface."
All photos from the BBC's archives. For more archive content visit BBC Rewind.