Bleeps, Blops, Clicks, and Pops

Sound Design in Games

Interactive: audio is triggered directly by player input or discrete events
Adaptive: audio changes in response to game state or parameter values
Common mappings
- Input → one-shot SFX
- State → music section or snapshot
- Parameter → continuous change of pitch, filter, send level

Diegetic: exists in the world; characters could hear it
Non-diegetic: player-facing guidance or score
Ambiguous cases to debate
- In-world radio that crossfades to score
- UI sounds that are framed as in-world devices

Layer	Primary goal	Pitfalls	Mix tools and policies
Ambience	Sense of place and time	Masking dialogue	EQ dips, level, bus ducking
World/Foley	Material identity, affordances	Repetition, machine-gun effect	Variations, random start, filters
UI/UX	Feedback and guidance	Loudness spikes, overuse	Loudness targets, short decay
Dialogue/VO	Intelligibility	Fighting music/ambience	Sidechain, clarity EQ
Music	Narrative pacing and emotion	Loop fatigue, clashes	Stingers, states, blends

There is no single codec that fits every audio use case; each has strengths for different scenarios.
Opus is best for compressing voice and dialog, combining high quality with small file sizes.
WAV/PCM offers the fastest decoding and no loss of quality but results in very large files.
Vorbis is a strong, widely compatible alternative when Opus isn’t available.
Hardware or software decoding methods can affect performance, so codec choice may depend on platform support.

ID	Asset Name	Category	Trigger/Event	Diegetic	Playback
01	footstep_grass_light	Foley	player_step	Yes	One-shot
02	door_metal_open	Foley	interact_open	Yes	One-shot
03	ui_inventory_open	UI/UX	ui_open	No	One-shot

ID	Variations	Randomization	Parameters	Ducking	Format
01	8	start ±20%, pitch ±3 st	player_speed	UI bus −4 dB, 50/200	OGG
02	3	start ±10%, vol ±2 dB	none	music bus −3 dB	WAV
03	2	none	none	none	OGG

Goal: Design a small assets list for footsteps that adapt to player_speed and surface.
Template

Steps

Groups of 3–4 choose one surface: grass, metal, water, stone
In the class Google Sheet (tab for your surface), fill 5 rows using: Asset Name · Category · Trigger/Event · Diegetic · Playback · Variations · Randomization · Parameters/RTPCs · Ducking · Priority · File Format
In Notes: define mappings (e.g., player_speed → pitch ±3 st, vol ±3 dB; crouch → high-cut)
Prepare a 1-minute rationale: how you avoid repetition and masking

Deliverable: Five rows completed + 1-minute talk-through

Asset Name Use snake_case with surface + action + intensity. Examples: footstep_grass_light, footstep_metal_heavy, ui_inventory_open
Category Broad grouping for mix policies: Ambience, Foley, UI, Dialogue, Music
Trigger/Event When the sound plays, written like an in-engine hook. Example: player_step(surface=stone)
Diegetic Yes = in the world (footsteps, doors). No = player-only (UI clicks)
Playback One-shot (footsteps, UI) vs. Loop (ambience beds, wind)
Variations Number of alternates to reduce repetition (e.g., 6–10 for footsteps)
Randomization Small changes per playback to humanize: Examples: start ±15%, pitch ±2 st, vol ±2 dB
Parameters/RTPCs Gameplay values that drive change. Examples: player_speed → pitch ±3 st, crouch → LPF 5 kHz
Ducking Sidechain to protect clarity. Example: UI −3 dB (attack 10 ms, release 200 ms)
Priority High (critical cues), Medium (most Foley), Low (ambience)
File Format OGG for runtime SFX/music, WAV/CAF for source/tight loops, AAC for streams
Notes Implementation details, test methods, or accessibility intent Example: “Caption: [Soft crunch]; Test: sweep player_speed 0–1, confirm smooth pitch change”

Mike Patton and the Intonarumori