vcmi/config/ambientSounds.json

{
  // By default SDL2_Mixer allocate 8 channels, but more sounds require more channels
  "allocateChannels" : 16,
  // Maximal ambient sounds volume must be about 20% of global effects volume
  "volume" : 20,
  // Maximal distance to objects using chebyshev distance
  "range" : 3,
  // Volume depend on distance, e.g 100% on same tile, 90% one tile away, etc
  "distances": [100, 90, 60, 30]
}