HPL3 uses FMOD to handle all sound playback. See fmod.org for more details, documentation and help. When working with sounds it is mainly the FMOD Ex Designer tool that will be of interest, the easiest way to learn how it works is to check the tutorials in FMOD's YouTube channel.
It is important to plan and think through how to split up your sounds into different projects. The game will load sounds based on this, it will help you find your sounds, it will ease preloading if you need to use that and so on.
Create a project for large chunks of sound types, for example a project for each character, level or for physics. Each project can contain many groups of sound events, preferably a hierarchy of 1-2 sub-groups will make it organized and easy to work with when for example optimizing. More details about this is found under FMOD Designer Events. Some type of sounds need to follow a special structure and naming convention! See the sections below, for example physics and footsteps.
A bank stores all the sounds for a project, you can have many banks but you should normally only need two. One bank for sounds that you load into memory to play and one bank that streams sounds from the harddrive and plays them. Special cases where you need to have more banks would be if you have sounds that are localized to different languages, where you have one bank for each language.
Sounds to be streamed are usually longer sounds, such as a looping ambient track or voices. Be cautious with using streamed sounds, streams depend on the speed of the harddrive, so what works well for you might not be so for another user. Try to keep the number of simultaneous streams to something low, perhaps max 6 streams. Remember that music and dialog streams, so could easily be 3 streams if you have a cross-fade of music going when a voice is played.
Our releases always have all the final FMOD project files in the game sound/ folder. The actual source sound files are not included, but you can view the projects and see how they are organized and what settings are used for reference.
A sound def is the settings for a sound (or set of sounds for variation) that you can use in your Multi-track events. There is nothing specific to keep in mind for these, do as suitable and follow the FMOD documentation.
The Events are what you actually use when playing sounds in the engine. The events are what replaces our old system of playing a SNT file, which essentially worked in the same way as Simple Events. When working with events there are a few things to keep in mind, mainly to organize events into easy to navigate groups and to use categories to send the events to be processed (or not processed) by the proper global effects.
Nothing in particular to keep in mind beyond the basic usage as specified by the FMOD documentation. Just check our general important notes for events and performance concerns for info on why you should use simple events and any minor specific setting you might need to set