Working mod: https://mega.nz/#!5poDCCrZ!VaR5oscyIoanNppsEe1n8kfy2GOELkgmoJ5OPsxe5AU
I'm not sure if I done everything right, but it works.
What I changed:
1. Factorio version in info.json (duh, obviously).
2. Copied demo-sounds.lua from game directory to mod directory (not sure if it is required. Maybe there's another way to call functions from it).
3. Added line 'local biter_sound = require ("demo-sounds")' at the start of mod data.lua (looks like sound functions were global before. Doesn't seem to be the case now).
4. Changed function calls to accomodate for 0.18.2 changes. For ex:
Line 68:
sound = make_biter_roars(0.8)
to
sound = biter_sound.biter_roars(0.8)

Step 2 you shouldn't need to copy, just include the file from __base__:
local sounds = require("__base__.prototypes.entity.demo-sounds")

A bit late but the mod is now updated to be compatible with 0.18

Step 2 you shouldn't need to copy, just include the file from __base__:
local sounds = require("__base__.prototypes.entity.demo-sounds")

Thanks!