Sound and Music
A developer adds sound to a project a week before release: grabs a free SFX library, scatters AudioSource components around the scene, sets background music on the camera. Launch the game—problems immediately apparent: all sounds at equal volume, a sniper shot as loud in the next room as point-blank, music cuts off abruptly on scene change.
Sound in games isn't a collection of .wav files. It's a system working in realtime, reacting to game state, creating spatial awareness and authenticity.
Tools: Unity Audio Mixer, FMOD, Wwise
Audio system choice determines possibilities for the entire project.
Unity Audio Mixer — built-in solution. Sufficient for simple projects: group sounds, apply effects (reverb, compressor, EQ), control volume via code. Zero integration friction—works out of the box. Limitation: no event model, no adaptive music, no proper tool for sound designer without Unity Editor access.
FMOD Studio — professional tool with separate editor. Sound designer works in FMOD independent of developers. Supports events, parameters, adaptive music, full 3D control. Integration via official Unity and Unreal plugin. For most mid-scale AA and indie projects—optimal choice.
Wwise — AAA-level industry standard. More powerful and complex than FMOD. Used in large studios with dedicated 5+ person audio teams. For small teams usually overkill.
Deeper: Spatial Audio and 3D Sound
Spatial audio distinguishes "sound in a game" from "sound in the game world." When a player hears footsteps behind them and turns the right direction—not chance, but result of proper setup.
Basic AudioSource Configuration in Unity
Each AudioSource with 3D Sound Settings enabled works as point source in space. Key parameters:
- Spatial Blend: 0 — fully 2D (UI sounds, music), 1 — fully 3D (game objects)
- Min Distance: distance to maximum volume. For pistol shot—2–5m, for explosion—20–50m
- Max Distance: distance to full silence
- Volume Rolloff: Linear easier to predict, Logarithmic closer to real sound behavior in physical space
Common mistake: leaving defaults (Min Distance: 1, Max Distance: 500) for all sources. Result: quiet leaf rustle heard across the map, explosion fades in two steps.
Audio Spatializer
Standard Unity audio calculates positioning through panning—sound goes left or right by angle. Flat model.
Audio Spatializer adds HRTF (Head-Related Transfer Function)—mathematical model of how ear perceives sound from different points in space, including height. Result: sound from above sounds different than from side or below.
For VR projects Spatializer isn't optional, it's mandatory: without it presence illusion breaks. For regular 3D games provides noticeable improvement in perception at minimal cost.
In Unity connected via Audio > Spatializer Plugin in Project Settings. Microsoft, Oculus, and Resonance Audio (Google) provide implementations.
Reverberation and Room Acoustics
Different spaces should sound different: cave differs from corridor, open street from carpeted room. For this use Audio Reverb Zones in Unity or reverb zones in FMOD.
Correct approach—not one reverb for entire scene, but zoning. Player enters cave—smooth crossfade to reverb with long decay. Exits to street—transition to short open space.
In FMOD implemented via Snapshot system: each audio snapshot stores mix parameters, transitions between them—crossfade with specified time.
Deeper: Adaptive Music
Linear background music—weakest solution. Player hears same exploration theme during combat. Or music cuts off abruptly on character death.
Adaptive music changes realtime based on game state. Two main approaches:
Horizontal Re-sequencing
Different musical segments play sequentially based on state. Exploration segment → transition → combat theme → transition → victory fanfare. Transitions recorded in advance, ensure smoothness.
In FMOD implemented via Transition Region and Timeline Markers. Developer calls eventInstance.setParameterByName("CombatIntensity", 1.0f)—FMOD finds nearest transition marker and switches segment seamlessly.
Vertical Layering
Same theme, but layers added or removed. In calm play—only piano and strings. Tension starts—percussion and brass added. Full combat—all layers active.
// Example of intensity control via FMOD
[SerializeField] private string _combatParameter = "CombatIntensity";
private FMOD.Studio.EventInstance _musicEvent;
public void SetCombatIntensity(float value) {
// 0.0 = calm, 1.0 = full combat
_musicEvent.setParameterByName(_combatParameter, value);
}
Vertical layering requires more composer work (all layers must harmonically coexist), but provides smooth transitions without audible seams.
SFX and Management via Audio Mixer
All sound effects grouped in Unity Audio Mixer or FMOD bus hierarchy:
Master
├── Music — background music
├── SFX
│ ├── Combat — gunshots, explosions
│ ├── Ambient — environment, nature
│ ├── Footsteps — character footsteps
│ └── UI — interface sounds
└── Voice — dialogue, voice lines
This structure allows:
- Globally regulate volume per category from game settings
- Apply different processing (Music compressor, SFX lowpass filter during pause)
- Ducking (auto volume reduction of music during dialogue via Side-Chain compressor)
What This Service Includes
- Select and configure audio system: Unity Audio Mixer, FMOD, Wwise—based on project scale
- Design bus and group hierarchy
- Configure 3D sound: falloff parameters, Spatializer, reverb zones
- Implement adaptive music (horizontal or vertical model)
- Integrate ready SFX and music tracks into engine
- Audit existing audio system: diagnose performance and quality issues