The business of silence: is there a hidden cost to noise cancelling?

Headphone and earplug sales are booming, but individual efforts to turn down the volume may alter our brains and surrounds in unexpected ways

Everywhere you look, it seems, people are resorting to accessories to turn down the volume of life: over-ear headphones on public transport, long-haul flights and in open-plan offices; coloured earplugs nestled discreetly in the concha of concertgoers, bartenders and, if you're a snorer, perhaps the person you share a bed with.

Silence is now big business: globally, the noise-cancelling headphones market generated $13.1bn in 2021, a figure that is expected to more than triple to $45.4bn by 2031, according to Allied Market Research data.