During cutscenes everything's normal. But there's no sound outside of cutscenes. Just dead silence.
What should I do? I can't find anything about this.
I'm on Windows 7 (64), turning off "advanced sound" option in the game doesn't change anything.

Edit: also in a window that opens when the game is running it says "gencfg.bat" is not recognized as an internal or external command, operable program or batch file
is that the problem?

I noticed there's a command on the launcher2.bat file like this:
cmd.exe /C gencfg.bat %CD%

When I do a seach for a gencfg.bat... well it seems there's no such thing on my computer.

Have you already tried starting the game with BADMOJO.EXE in the game's installation folder. If it doesn't run, try using compatibility mode for Windows XP. Right-click the file => Preferences => Compatibility tab.

Btw, the gencfg.bat doesn't run on my system either, but I do hear in-game sounds.

The only difference running Badmojo.exe makes is the game's screen is smaller, but I still get no sound :/
Ironically I get an error trying to run it in compatibility mode, but it runs fine normally (just no sound)

Make sure all older components of DirectX9 are present on your system, by installing the following DirectX End-User Runtimes (June 2010): http://www.microsoft.com/en-us/download/details.aspx?id=8109
Run the file and extract the content to a separate folder, then use dxsetup.exe to start the installation.

Don't install the game into Program Files, but into a custom location like C:\GOG Games\
Try running it as admin, by right-clicking the file to start and select Run as administrator.

Check the badmojo.ini file in the game's installation folder. It should look like this:
...
SOUND=<path to the sound folder>
...
[SoundMix]
SoundOn=1
BetweenScreens=1
SmallChunkSize=3
BigChunkSize=26
BigChunkMethod=0
DumbSound=0

Make sure there's no other badmojo.ini file on your system (especially not in C:\Windows or in a subfolder of C:\Users\<current logged in user>\AppData\Local\VirtualStore\)

Thanks for the suggestions, I followed them but no luck. Game's installed to "C:\BadMojo" btw.

Hmm, odd. What kind of sound chip are you using? Have you tried updating its drivers. Are there any known issues with DirectX9 compatibility?

I'll have to look into that... I'm a complete n00b about audio :/ Never had a problem with it before, though it's pretty old. There's a VIA High Definition Audio thing and a NVIDIA thing (?).
Should I contact GOG support and see if they can help me anyway?

Dxdiag gives me a bunch of info I'm not smart enough to understand...

I got the game to work on my laptop, sound seems to be working. Pitty I hate laptop screens and audio (also not a fan of headphones). But if if all else fails on my desktop pc at least I have a way to play it.

Shoot a ticket to support, that never hurts. You have to attach a Dxdiag report, which will reveal if there are any incompatibilities.
My guess is the VIA sound chip is compatible though. The NVIDIA thing is you graphics chip, if there's sound involved, then only because of an HDMI audio output. That doesn't affect the game. Generally it's working anyway, as the Quicktime movies have sound, only the in-game Wave sounds are muted.

Thanks, I will. And thanks for the tips and trying to help :)
Trying to auto update the drivers tells me they're up to date, if that's worth anything

Edit: when I try playing the wav files in the sound folder, I can't hear anything..... is this normal?

Can anyone tell me how long GOG takes to answer support tickets?

I have another sound problem with a different old game (Syberia) :/ Edit: AAAAAND another game: Sanitarium. Dammit!

I'm tempted to buy these games on Steam just to see if they work there.

No, definitely not. Looks like wave output is muted on your system anyhow or maybe your system codecs for wave are screwed.

Download VLC player and check if the waves play with it.

Oh, thanks, they play on VLC! So I guess back to square one?

GOG support has gotten back to me but they're suggesting usual "how to make sound work on pc" run of the mill stuff, obviously I DO get sound, just not in those very specific circunstances....
Trying to update sound drivers but uhh this is the part I'm totally confused about... depending on where I look I get a different info on what audio I have. I guess some things I just can't wrap my head around. I'll try a few things and write if I happen to get something right.

I know this is rather late but may be useful if anyone else runs into this problem. I had the exact same problem. Cutscenes had sound but nothing else. When I checked my sound properties I saw that I was having output on the digital output instead of the speakers. A reboot simply fixed my problem, but it looks like it just may have been sending the wav to the wrong output.