I laughed at a joke. It was no joke.

On mishearing and assumptions and the things we add ourselves..

I was at a party, standing in the particular configuration I've perfected over the years: the person I was talking to positioned slightly to my left, my good ear angled towards them, my face arranged into an expression of intelligent attention. Their expression invited a response, so I supplied the missing words, and they were funny, so I laughed. Heartily.

Only they hadn't made a joke, they were telling me about their dad's dementia. It is a very particular social manoeuvre – retrieving a laugh once you've released it – one that I have had a lot of practice in, unfortunately. This is because I have no useful hearing in my right ear. Calling it a disability feels like I am taking something away from people who have far worse to manage. It's an invisible inconvenience, that's all. In restaurants, I try not to put my deaf ear towards the table. I may have to swap sides when I'm walking with someone. People who know me well know why I do these things. People who don't may think I'm eccentric. I don't care.

Whenever I don't hear something, I have choices – sensible choices – like asking the other person to repeat themselves. I used to quite like the phrase 'I beg your pardon' as a child, it sounded fancy – unfortunately it can also come across as rude. So most of the time I choose to guess.

What gets me isn't that I sometimes get it wrong, it's how completely right I can feel while doing it. When part of a sentence disappears, my brain doesn't leave a neat little blank like one of the comprehension exercises. It fills it immediately using context, facial expression, what was said a moment ago and, inevitably, what I expect the other person to say. Most of the time this works brilliantly. Most of the time, but…​

I once caused panic when I constructed a medical emergency because someone announced they were going to get drinks. I only heard the hospital part of hospitality tent and must have invented something more serious than feeling parched.

Recently I've started to wonder if this is peculiar to being deaf in one ear. I think everyone is at it. We hear a few words and supply the rest. Someone says, 'Can I just say something?' and before they've said it, we're preparing our defence. A colleague pauses in a meeting; we decide they're unconvinced. A friend sends 'Fine.' and we hear the full stop.

We don't only listen to what people say, we listen through everything we already believe about them. The person we're listening to is, at least in part, a person we've invented.

I think about this a lot when I'm directing actors. A script provides words printed on the page; everyone can see exactly what is to be said. However, a line can contain completely different meanings depending on who is saying it, what they want, what they're hiding, what happened thirty seconds earlier. One of the pleasures of directing is discovering that an actor has heard something in a scene that I haven't. My instinct used to be to explain the intention: this is what the character is thinking, this is what the scene is doing. But explanation can close something that was still usefully open.

What did you hear in it?

Not: did you not understand what I meant?

We talk about listening as though it were principally an act of concentration: stop talking, pay attention, don't interrupt. I'm interested in another part of it – noticing what we've added ourselves: the missing word, the motive we assumed, the tone that was never in their voice, the ending we'd written before they got anywhere near it. 

My deafness, it turns out, is a great excuse for something we all do.

Hearing what someone says and misunderstanding them anyway.