One thing you notice at the family-friendly festival Latitude, now into its final day, is the effect of noise on the various age ranges here.

You can see babies blissfully asleep where there is blaring music, because they are able to filter out noise. Human babies are among the most adult-dependent of all animal species which is what allows them to develop. This means they don’t have to be alert to different noises while they sleep.

But as we grow older this changes, and our brain needs to know which new sounds present a threat. Parents are less able to switch off and if we can fall asleep, sounds are often incorporated into our dreams. But it’s the novelty rather than the volume of the noises which we need to tune into. The loud rumble of a regular bus passing outside our window does not trigger us at home, but sleeping in a tent, the full gamut of unusual nightime activities make themselves heard, so our brain will wake us for a full analysis.

If your chosen substance does not promote sleep, you’d better pack your earplugs. Your babies won’t need them, but you probably will.

Dr Daniel Glaser is director of Science Gallery at King’s College London