In the programme of Scottish National Orchestra concerts to which my Mum and I used to go on Friday nights, there was a courteous announcement about coughing. It explained that an ‘unmuffled’ cough in the concert hall had been found to be about as loud as a note played mezzo-forte on the French horn. Audiences were politely requested to use a handkerchief to muffle the sound of a cough. The sucking of boiled sweets was recommended as a way to avoid coughing in the concert.

I remember reading research from the Common Cold Centre some years later which measured a cough at an average of 70–90 decibels, described as ‘like a noisy radio or the sound of a tube train’. This image was somewhat more arresting than ‘a note played mezzo-forte on the French horn’. The loudest cough they'd measured was, it turned out, not much quieter than a pneumatic drill. Coughs were said to be ‘like a football crowd roar’. All these comparisons are, of course, slightly misleading because they bring to mind a continuous sound event, whereas a cough is usually an explosive single moment. But it's useful to make people aware of how disturbing a cough can be.