How-to: Make a sound-effect sound like it's in the distance...

Three things happen to a sound as it travels across distance:

1. It gets quieter (that bit’s obvious to most people).
2. It gains echoes/reverbs.
3. Higher frequencies are lost faster than low frequencies.

Number 1 is easy to achieve.

For 2 and 3. you will need either an effects box and graphic equaliser, or audio editing software such as Audacity (which is free, and my preferred software for sound-effects work).

The amount, and kind of echo you will want will depend on the kind of environment the sound has travelled through, the larger the environment, the longer the reverb time. The rate of decay will depend on the material that the sound is bouncing off. If the sound has been bouncing off hard surfaces in a closed environment then the decay will be quite slow, but in an open environment such as a woods the decay will be quite fast. Generally I keep the reverb quite subtle, with a high decay.

If you go and listen to a far away sound, such as traffic noise, you will notice that it sounds muffled when compared to near-by traffic noise. This muffling is due to a loss of the higher frequencies in the sound. To simulate this, use a graphic equaliser and turn down each frequency band more as you go up the frequency range. You’ll end up with a slope starting high on the left, and ending low on the right on most EQs.

By combining these two together, you can create a range of distance effects, ranging from “down a corridor” to “out in the woods”.