Defining what a sound means

A rising chime means something good has happened, a dull thud means it has not, and nobody who works in audio needs that explained to them.

British regulators have taken that everyday understanding and tried to write it down as a requirement: online casino games are no longer permitted to play a winning sound when the player has lost money.

Putting it into a rulebook sounded straightforward enough. It has not been, and researchers have now tested the rule against the games themselves. What they found will be familiar to anyone who has taken a script through clearance and been told the wording is fine but the delivery is not.

When a Happy Sound Means You Lost

A slot game spreads one bet across several possible combinations at once, so a single spin can pay out on some of them and lose on the rest. Stake 90p, get 30p back, and you are 60p worse off on that go, but because part of the spin did pay, the game answers with the same cheerful chime it uses when you finish ahead. Lose the whole 90p and it says nothing at all.

Researchers call the first of those outcomes a loss disguised as a win, and the name captures the problem neatly, because the audio says one thing while the balance says another. On a fast game, checking the running total after every spin takes longer than listening, so the sound gets there first and tends to win the argument.

Nothing about that spin is hidden. The return percentage, the stake range and the terms of any deposit offer are all published, and a layer of independent review sites exists to pull those numbers together and compare operators against each other. A UK team of that kind sets out Legalbet’s £20 deposit deals with the wagering rules attached to each one. All of it sits in writing, available before a player commits anything. The audio is the one part of the transaction that arrives without warning and disappears immediately.

What the British Rule Says

Requirement 14F of the Gambling Commission’s technical standards for online games runs to a single sentence: the system must not celebrate a return that is less than or equal to the total stake. The guidance defines “celebrate” as the use of sound or visual effects associated with a win. Slot games came under the rule on 31 October 2021, as part of a wider set of changes to how they behave:

• Players must confirm each spin themselves, which removed automatic play
• No turbo or quick-spin buttons to hurry the outcome along
• No operator feature for running several games at the same time
• A minimum of 2.5 seconds per spin
• An on-screen running total of money won or lost and time spent playing

Other casino games followed on 17 January 2025, when the Commission extended the same restriction beyond slots alone. Regulating the sound of a losing outcome is a recent idea anywhere, so there was little to borrow from when the sentence was drafted, and the open question is whether one sentence can carry that much weight.

Where the Definition Runs Out

The journal Behavioural Public Policy published a study in February 2026 by Dan Myles and Daniel Bennett of the University of Melbourne, with Philip Newall of the University of Bristol. They worked through 26 online slot games available to UK players, listening to what happened after a partial payout. In 17 of them the sound came from the same family as the one used for genuine wins, and in 18 the researchers judged the effect celebratory.

Whether a sound counts as celebratory is a judgement call, so the team put their own judgement to the test. Four hundred UK gamblers listened to recordings pulled from the games and said whether each one signalled a good outcome. The listeners agreed with the researchers every time, which suggests the assessments rested on something firmer than academic taste.

Nothing in the paper accuses studios of breaking the rule, and the argument the authors make is narrower than that. A developer can use one sound after a win and a different one after a partial payout, and the requirement is satisfied, because the two are not the same effect. Whether the second still sounds like good news to the person hearing it is a question the wording never asks.

Developers flagged the same gap from their own side during the consultation in 2023, arguing that the wording would force them to add a second sound to games designed with only one, and that a sound which is not celebratory in character needs no separate version at all. Live dealer tables came up as well, since a presenter talking to players might congratulate somebody without thinking about it.

Why Turning the Sound Off Is Not the Answer

A group at the University of Waterloo led by Mike Dixon, working with Karen Collins and Kevin Harrigan, measured what players’ bodies do during play, tracking heart rate and the faint sweat response the skin produces when a person is excited. On partial payouts those readings sat closer to a real win than to a total loss. Asked afterwards how often they had come out ahead, players overestimated.

Pairing those partial payouts with a negative sound changed the picture entirely. Most players then identified the spins correctly as losses, and their estimates of how often they had won became much more accurate. Cutting the audio altogether made far less difference, which points to meaning rather than volume. The Bristol and Melbourne team made the same case by measuring their recordings against three sounds from ordinary life: a fanfare from Wheel of Fortune, the tone Apple Pay makes when a payment goes through, and the coin pickup from Super Mario Bros. Nobody has to be taught to hear those as positive.

Radio Has Been Writing These Rules for Decades

Section 2 of the BCAP Code, which covers advertising on Ofcom-licensed radio and television, has been dealing with this same problem for years, and approaches it in three places:

• Advertisements must be obviously distinguishable from editorial content, especially when they borrow a style that resembles it
• A phrase or sound effect linked to news bulletins or public service announcements, with “news flash” given as the example, needs special care
• A title, logo or piece of music associated with a programme on the same station needs special care

Radiocentre’s copy guidance fills in what that means in practice. An advert imitating editorial should normally be separated from the programme by a jingle, a station ident or an intro into the break, and news-bulletin styling is acceptable as long as the listener works out quickly that this is an advert. Before a national commercial airs, it goes to Radiocentre for clearance, so somebody listens and forms a view about what the audio implies while the script can still be rewritten.

The BCAP Code carries one further line with no equivalent in the standards for casino games: advertisements must reflect the spirit, not merely the letter, of the Code. That clause exists because compliance with the letter alone is precisely what a rule about implied meaning invites.

What This Says About Writing Rules for Audio

Both sets of rules are aimed at a conclusion the listener draws rather than at the sound itself, because a chime states nothing on its own and the meaning comes from the person hearing it. Write the rule around technical facts, such as which file plays and when, and it can be followed to the letter without changing what anyone hears. Write it around the meaning and somebody has to sit down and make a judgement. Radio kept clearance in the process for that reason, and the researchers want requirement 14F amended rather than scrapped for the same one.

A two-second cue makes a claim, and claims attract regulation once money is riding on them. Radio learned that slowly, through clearance notes and rulings stretching back decades. Game sound has reached the same point only recently, though with one advantage broadcasting never had when its own rules were drafted: hard evidence about how listeners decode a sound.