AUDIO: Laura Bow 2 ladder sound not playing in 2 of the 3 Adlib emulators

[sluicebox]

There's a sound in the SCI game Laura Bow 2 that doesn't play in ScummVM in the default configuration. Two of the Adlib emulators don't play the sound, but one does. MAME and DOSBox OPL emulators don't work, but Nuked does. DOSBox (the program) plays the sound just fine. Other emulators like PC Speaker and MT-32 work.

In room 610 there are ladders. When you climb up and down them, the script plays SCI sound 613 on every step. This is a very short one-note sound, it's supposed to be the "ping" of stepping on a metal rung, so you should hear many of them. You can change the game speed in the control panel to slow down or speed up this animation and the delay between each sound -- the bug happens at all speeds.

My guess is that the problem has to do with the unusually short duration of the sound. The SCI sound engine appears to be doing all the right things. I don't know about the low-level driver/hardware emulation stuff.

To reproduce with any version of LB2:

• Set music device to Adlib emulator
• Set Adlib emulator to MAME or DOSBox
• Go to room 610 (room 610 in ScummVM debugger)
• Click the Do (hand) cursor on a ladder

The ladder sound won't play. Set Adlib emulator to Nuked and it will.

I tested with very old versions of ScummVM and got the same results, so this isn't a regression. I'm using Windows builds.