Audio Modding

Audio Modding with FMOD Studio

Last updated: April 3, 2026 Introduction This guide is not a replacement for the official FMOD Studio manual. If you’re completely new to FMOD Studio or audio middleware in general, we recommend starting with the official documentation on FMOD’s website before diving in here. The purpose of this guide is to give you an up-to-date, Bannerlord-specific reference that helps you work efficiently with FMOD. It focuses on workflows, best practices, and performance considerations that are unique to Mount & Blade II: Bannerlord.

Event Setup

Last updated: April 3, 2026 Parameters Parameters in FMOD Studio are variables that control how an event behaves during playback. They can drive changes in volume, pitch, filters, instrument playback, or event logic — making sounds dynamic and responsive rather than static. Each parameter has a name, a range of values, and a type. During gameplay, your code can set or adjust these values, or they can be driven automatically by game states, distance, velocity, or other inputs.

Scene Audio

Last updated: April 3, 2026 Adding Sound Entities In our proprietary game engine, placing sounds into a scene is straightforward. Start by creating an empty entity in the scene. Once the entity is added, select it in the scene hierarchy to open the Inspector Window. If the Inspector doesn’t appear, enable it through Window > Inspector Window. In the Inspector, expand the Scripts dropdown and choose Add New Script. From the dialog, select AmbientSoundEmitter to attach a sound emitter script to the entity.

Audio Systems & Optimization

Last updated: April 3, 2026 Voice System Non-dialogue vocalizations for humans, mounts, and animals (grunts, pain sounds, commands, etc.) are not hardcoded into game logic. Instead, they’re managed through an external configuration file called voice_definitions.xml. This makes it straightforward to add or adjust voices without touching code. All declarations and definitions are written in XML and link directly to FMOD event paths. File path: ..\Modules\Native\ModuleData\voice_definitions.xml Voice Type Declarations Before a voice can be used, it must be declared under the <voice_type_declarations> section.

Adding Sounds to Your Module (Outdated)

Bannerlord audio system is built on proprietary FMOD Sound system. To keep audio engine performant while making it accessible to anyone, we needed to create an interlayer. Key Elements ...\Modules\*YOUR_MOD*\ModuleData\module_sounds.xml file, where you add custom definitions for your own sounds ...\Modules\*YOUR_MOD*\ModuleSounds folder where you put audio files (.ogg, .wav) You can see examples in ‘Native’ module. Basic Guide Copy example files and folder to your own module Add new sounds into the ModuleSounds folder Open the module_sounds.