We were changing a very tired baby last night and she started screaming hysterically. It’s not like her at all. Then out of nowhere we heard music.

‘What’s that?’ I thought maybe I was imagining it.

‘Is it your phone?’ said Damjan.

‘Sounds like… lullabies…’ I said, holding down flailing arms as Damjan tried to thread them through the sleeves.

‘Like the cot mobile?’

We stared at the cot mobile, which wasn’t lit up or spinning as it normally is when it’s on. I leaned in to listen.

‘It is from the mobile!’ I was astonished.

‘It must turn on when the baby cries.’

‘That’s crazy! I’m looking that up on the internet.’

Sure enough, the VTech cot mobile I bought for $20 off Gumtree, without instructions, has a sound sensor that turns on soothing music when a baby wakes up and cries.