Sensory overload

Overload is about volume of input over time, not a single loud noise. Ordinary things stack up: the lighting, the background chatter, a jumper’s label, movement at the edge of vision, a smell from the kitchen. Each one is minor on its own. Together, and hour after hour, they use up the spare capacity the brain needs to filter and prioritise, until there is none left and everything comes through at once.

It is common in autistic and ADHD people, and in people living with PTSD, because all three involve differences in how sensory input is sorted and ranked. One useful idea here is monotropism (mon-oh-TROH-pizm), set out by Murray, Lesser and Lawson: attention tends to pool deeply on a narrow channel, which is a strength when focused, but makes handling several competing inputs at once far more costly. The National Autistic Society’s guidance on sensory differences frames it the same way. The word to hold on to is load. Overload is not being “too sensitive”; it is a system that has run out of room.

If this is part of your wiring, some of this will be familiar. The supermarket, with its strip lighting, tannoy, trolley noise and shelf after shelf of choices, and by the third aisle your thinking has gone loud and slow. The open-plan office through the afternoon, where the hum and the half-heard calls add up until a two-line email takes three attempts. The dishwasher starting at 9pm and landing as though it is inside your skull, when the same sound barely registered that morning, because your capacity is lower by the end of the day.

The after-effects are as much a part of the pattern as the spike:

• shutdown, where you go quiet and flat and cannot easily speak or decide
• irritability that is really the nervous system asking for less
• a heavy tiredness that outlasts whatever set it off

When this keeps happening without enough recovery, it is one of the things that feeds autistic burnout. Recognising the shape of it, spike then after-effects, is the first step to planning around it.

Filtering is not free. Broadbent’s filter model describes attention as a bottleneck: input you are trying to ignore still has to be detected and actively held back, and that holding back is work. For someone whose filter is already stretched, “just tune it out” asks the tired part of the system to do more, so the overload arrives sooner, not later.

Predictability and control change the cost too. A noise you can stop, or that you know is coming, loads you far less than the identical noise you cannot. That is why other people’s ordinary sounds are often harder to bear than your own, and why an unpredictable environment drains you faster than a loud but steady one. None of this is a matter of attitude. Naming the mechanism is not an excuse; it is the difference between spending effort on the right thing and wasting it on the wrong one.

In-the-moment help and prevention are two different jobs. When overload is already building, the aim is simply to lower the input and get clear:

• reusable filter earplugs or noise-cancelling earbuds (brands like Loop or Calmer) that take the edge off sound without cutting you off from conversation
• tinted lenses, or a cap, to soften harsh overhead lighting
• stepping outside for a few minutes, or leaving early without a long explanation, which you do not owe anyone
• having a trusted person leave the room or the venue with you, so getting out does not become its own social hurdle

None of these fix the cause. They stop the spike getting worse while you put distance between yourself and it, which is often all that is needed to recover.

The biggest gains come from prevention, from shaping the places you spend time in so the load never stacks as high. Over a week, small defaults add up:

• warmer, more predictable lighting in place of overhead fluorescents wherever you can change it
• soft furnishings such as rugs, curtains and cushions to dampen the hard echo that makes a room feel louder than it is
• scheduling the most sensory-demanding tasks for your lower-load times of day, and keeping a quiet gap straight afterwards
• telling people your capacity in advance, so a quiet request to turn something down later is not misread as a sudden mood

At work this is not a favour. Under the Equality Act 2010, employers must make reasonable adjustments for disabled employees, and sensory needs count. Reasonable asks include a quieter desk, agreement to wear ear defenders, meetings with agendas sent ahead, or working from home on high-load days. Gov.uk sets out the right in plain terms if you need to point an employer to it.

The most useful thing anyone can do is believe it the first time it is mentioned. “But it’s not that loud” tries to negotiate with something that is not up for negotiation, and it quietly teaches the person not to tell you next time. A few defaults make a real difference:

• choose lower-load places by default, a quiet café over a busy bar, rather than making it a special request each time
• accept “I need to leave” as a complete sentence, with no debrief demanded afterwards
• at home, ask before adding sound, such as a second screen or the radio on top of the television, when someone is clearly running low
• don’t take the earplugs or the early exit personally; they are how someone stays in your company, not a verdict on it

Small, consistent adjustments from the people nearby often do more than any single piece of kit.