It’s now part of daily life for many of us – struggling to work out what someone in a supermarket or at work is saying when they’re wearing a face mask.
But for people who are deaf or have hearing loss, masks can prevent them understanding anything at all.
“You might as well be speaking in French,” says Fizz Izagaren, a paediatric doctor in the UK who has been profoundly deaf since the age of two.
“I can hear one or two words but it’s random, it makes no sense… When someone is wearing a face mask I’ve lost the ability to lip read and I’ve lost facial expressions – I have lost the key things that make a sentence.”
It is a problem she shares with the some 466 million people around the world who, according to the World Health Organization, have disabling hearing loss.
Standard face masks, which have become widespread as countries try to stop the spread of coronavirus, muffle words and obscure the mouth.
But now charities and manufacturers alike are coming up with a solution.