A game sound effect exists to be noticed. Its job is to tell the player that something happened — a hit landed, a coin was collected, a menu registered a tap — and it succeeds by cutting through the mix and arriving at the moment the player needs it. A focus app’s background sound has the opposite job. It succeeds when the user stops hearing it, and it fails the moment it becomes something the attention has to manage.
That inversion produces a chain of design consequences. Game SFX optimises for salience; a focus app’s ambience has to yield. Game SFX benefits from variation; a focus app’s variation starts becoming a distraction past a certain threshold. Game SFX can hide its loop point behind action; a focus app’s loop point has to be inaudible when the user is doing nothing else. The sections below work through those inversions in order of how hard the constraint is, with the parameters that follow from each.
Game SFX Is Designed to Be Noticed; a Focus App’s Ambience Is Designed to Be Ignored
The difference is a functional definition, not a stylistic preference. A 2021 study used EEG headbands to measure concentration in 51 people working from home under different audio conditions. Personalised soundscapes raised concentration significantly above the quiet baseline, but the effect depended on task type and age: for the “work” group, the soundscape condition produced higher concentration than silence; for the “non-work” group (reading, knitting, gaming, and similar), there was no significant difference. In the same study, 35.3% of participants concentrated best with the soundscape, 27.5% with an Apple playlist, 19.6% with Spotify, and 17.6% in silence.
Two things follow from that data. First, a focus app’s ambience is not universally effective; it works for some tasks and some people, and the design goal should not be “make everyone more focused” but “do nothing that harms focus.” Second, if a meaningful share of users focus best in silence, the ambience has to treat “not being noticed” as the default definition of success, not “being felt” as the default. A game sound effect can be remembered by the player; a focus app’s ambience that gets remembered is probably already interfering.
The Exposure Ceiling Is 80 dB Over 40 Hours — and That Is Not a Working Level
The WHO hearing-safety standard specifies two reference exposure modes: 80 dB(A) for 40 hours per week for adults, and 75 dB(A) for 40 hours per week for children or users who benefit from a lower level. That is a safety ceiling, not a recommended listening level. A focus app is used for long, continuous sessions, often several hours a day — exactly the pattern where exposure dose accumulates.
The design consequence is specific. The ambience cannot rely on high level to overpower environmental noise, because the user is likely already in a noisy café, an open-plan office, or transit, and has already raised the system volume to compensate. An ambience that sounds “just right” in a quiet room becomes a continuous high-dose exposure once the user turns the volume up to fight the background. The WHO model is 80 dB for 40 hours and 90 dB for 4 hours; every additional 10 dB cuts the safe duration to a quarter. A focus app cannot control the volume knob, but it can control crest factor and spectral distribution so the sound masks effectively at a low level rather than forcing the level up.
This is directly opposite to game SFX practice. Game effects often raise peak level and add low-frequency energy to create impact, because the player is actively engaged and the impact is brief. A focus app’s ambience is continuous, with no “brief” buffer. A sustained low-frequency rumble at an 80 dB ceiling produces a far higher exposure dose than a 200 ms game explosion at the same peak. The ambience has to be designed for sustained exposure, not for transient impact.
Cognitive Load: Lyrics and High-Intensity Music Interfere, and “White Noise” Is Not Automatically More Focused Than Pink
The cognitive-load literature is more specific than “music helps” or “music hurts.” A 2025 study found that background music with lyrics produced a general interference effect in reading tasks, especially in second-language reading, driven by semantic interference mechanisms. A study of Taiwanese university students found that higher-intensity music was more interfering, with a greater effect on task performance and concentration. A 2026 study found that self-selected music had no significant effect on reading comprehension in undergraduates — participants performed comparably with music, background noise, and silence.
Read together, those results do not support “music is good” or “music is bad.” They point at which properties of a sound consume cognitive resources. Lyrics consume language-processing resources, high level consumes arousal-regulation resources, and self-selected music can be non-interfering because its predictability and semantic load are under the listener’s control. For a focus app, the implication is to remove semantic content and unpredictable strong events, not simply to “play some nature sounds.”
The colour-of-noise claim needs correction too. White, pink, and brown noise are often assigned different cognitive effects in popular writing — white for masking, pink as “softer,” brown as “better for focus.” A 2025 pupillometry study found no significant difference between the three in sustained pupil-linked arousal, and the authors explicitly noted that the finding “challenges the assumption that spectral slope predicts autonomic arousal.” That does not mean the colours are subjectively identical — many users do find pink more comfortable than white — but it does mean that “brown noise is physiologically more focusing” is not supported by direct evidence. A focus app should choose the colour by user preference and masking need, not by an unverified “focus colour.”
Seamless Looping Means “Inaudible When the User’s Attention Is Idle,” Not “No Clicks”
Game ambience is usually masked by action: a loop runs under combat, dialogue, or music, and the loop point is hidden by other events. A focus app’s ambience has no such cover. The user may be reading, coding, or thinking in silence, and the ambience is the only thing playing — the loop point is exposed at the moment attention is least occupied.
The technical requirement is therefore stricter than in a game. One audio-production guide gives concrete parameters: crossfades should use an equal-power (logarithmic) curve, last between 500 milliseconds and 5 seconds so the loop’s overall feel is not changed while the transition stays comfortable, and the loop start and end should sit on zero crossings to avoid clicks. Another guide recommends starting the crossfade at 10% of the loop’s total length and then adjusting by ear. If the loop contains a reverb tail, the fade-out may need one second or more to end smoothly.
Those numbers address different failure modes. A crossfade that is too short — 50 ms, say — produces an audible dip on dense textures; one that is too long — ten seconds or more — blurs the loop’s structure until the sound loses its identity. Zero-crossing placement handles clicks, but clicks are only the crudest failure. The subtler failure is loop recognisability: once the same 30-second texture has repeated ten times, the user starts predicting the next event, and the loop stops reading as background and starts reading as a pattern — and a pattern is exactly what attention is built to parse.
Variation: Game SFX Uses It to Avoid Repetition; a Focus App Uses It to Avoid Being Predictable Enough to Notice
A game’s variation system exists to prevent the machine-gun effect: the same file repeated too often gets flagged by the ear as an artificial sample. A focus app faces a different problem. Its ambience usually has low event density (rain, wind, brown noise), so the per-event repetition is less sharp, but macro-level predictability shows up after long use. A user who has listened to the same rain loop for three weeks starts noticing “this part again.”
Endel’s design strategy targets exactly that problem: its soundscapes “never quite repeat the same way twice,” not by randomising individual samples but by generating continuous change at a macro time scale, partly solving the “user notices repetition after months” problem. Brain.fm takes a different route: its music is structural, layered, and forward-moving, but deliberately stripped of lyrics and hooks — the elements that grab attention — with the goal of doing continuous background work rather than creating interest through variation.
The two strategies correspond to two different variation budgets. Generative continuous change suits long, low-density ambience because its variation is slow and unpredictable and never forms a parseable pattern. Structural music suits work that needs some rhythmic support, but its variation has to happen inside the music, not through sudden events that create contrast. A focus app’s ambience that drops an obvious event into the background — a bird call, a thunderclap, a melodic turn — briefly becomes a game sound effect and asks attention to process it.
A Pass-Through Check: If the User Can Describe the Sound’s Structure, It Is Already Too Salient
A focus app’s ambience and a game sound effect share techniques — looping, layering, frequency management — but their acceptance criteria are opposites. A game sound effect’s acceptance question is “can the player notice it?” A focus app’s ambience acceptance question is “after twenty minutes of work, can the user still treat it as background?”
One workable check is to ask a user, after twenty minutes of use, to describe what they heard. If they can say “there was rain, then a stretch of thunder, then it turned into wind,” the sound has crossed the background boundary and entered a parsed pattern. If the answer is “I forgot what it was playing, but it felt empty when I turned it off,” the sound did its job. That does not mean the ambience must be featureless — the user should be able to recognise “this is rain” rather than “this is brown noise” — but the sound’s structure should not be something attention can track.
A second, reverse check: turn the sound off and see whether the user notices immediately. If they find the silence uncomfortable, the sound was providing masking without becoming a burden. If they feel nothing, either the sound was not doing any work or it had been fully ignored — the latter is technically success for a focus app, but it needs confirming that it was not ignored to the point of failing to mask.
Game SFX and focus-app ambience share a lot of technique: looping, layering, frequency management, variation systems. But their success conditions are opposite. A game sound effect succeeds by being remembered, identified, and treated as part of the feedback; a focus app’s ambience succeeds by not being remembered, not being tracked, and only being noticed as masking when it stops. The hardest thing for a sound designer moving from games to focus apps is not the toolset. It is replacing “is this sound catchy enough” with “will this sound make the user notice it twenty minutes into their work.” The first can be solved with peaks and transients. The second can only be solved with restraint.