The soft ticking of a wall clock, the clicking of heels on the pavement, the rustling of leaves - they are sounds most of us hear without even being aware of them.
Our brains are capable of registering dozens of sounds every second and quickly dismissing those that don't need our immediate attention.
Imagine a 61-year-old who has never heard any of them, and the tap of a computer key changing that for ever. For Peter Johnston, my brother-in-law, that miracle of sound happened two months ago. It ended a lifetime of hearing only the very loudest of sounds - the sorts of noises that would make most people wince, like a chainsaw, a jumbo jet or a heavy door slamming in the wind.
Born profoundly deaf in both ears, Peter had never heard the high-pitched squeals of his grandchildren calling to him to catch a ball, or the music of the Michael Jackson Thriller album downloaded on his phone.
But thanks to the cochlear implant once considered unsuitable for adults deaf since birth, Peter can now hear the world around him, sounds as basic as his car indicator when he turns at an intersection.
The father of three and grandfather of four cannot stop smiling since his implant was turned on in early July.
And he has experienced something he would never have thought possible: finding some noises too loud, like the roar of the crowd at the football when he goes to watch his beloved Dockers.
"Yes, I can hear it," he says. "It's loud. It's very noisy."
The chance for him to hear everyday sounds and conversation has been a long time coming.
Despite using hearing aids since he was a toddler, Peter had heard little other than very loud sounds.
When a hearing test at the age of 18 months revealed he was deaf, he became one of the youngest children in WA to be fitted with a hearing aid.
He went to the school for the deaf, learnt sign language and grew up part of the deaf community and culture he still embraces.
After leaving school at 16, Peter did an apprenticeship to become a car spray painter, married Sue, also deaf since birth, and had a family.
Life was good, if mostly silent.
Following cochlear implant surgery in June - at a cost of $31,000 paid by his private health insurance - he was finally "switched on" at Royal Perth Hospital's ear clinic a few weeks ago.
Now every day he discovers all the things he did not know made noise.
Peter notices the scuffling sound of his jeans as he pulls them on and the swish of a sports jacket going over his head. He remarks on the noise from dishes being washed in the sink, or the flash of a camera, or a winter cough.
Having a cochlear implant is tiring at first. Every sound is sharp, demanding his attention.
Sometimes he finds it overwhelming because he is still learning to filter out all the less important sounds.
He is intrigued by people's voices - from the high-pitch of his granddaughter to the deep, low frequency tones of his son.
Having a cochlear implant was a big step for Peter because some people in the deaf community are against the technology.
They argue deafness is not a disease that needs to be fixed and strongly oppose putting implants in young children and babies.
Until recently, Peter was unlikely to have been considered suitable for an implant because it was widely felt the technology helped only adults who were born with normal hearing, learnt to talk and then lost their hearing through injury or ageing.
It was considered too big a leap to expect people deaf from birth who had missed out on a lifetime of hearing and language to suddenly adapt to the hearing world.
Peter has done just that. His eldest son Philip, 36, says it has been incredible to watch his father hearing sounds that everyone else takes for granted.
"If it wasn't for this technology, he would never have known all this, and not heard his grandchildren's voices," Philip says.
Peter also owes a lot to his parents, Margaret and Gordon, who persisted at making him wear hearing aids, even when he was a frustrated little boy who threw tantrums and regularly pulled out his ear moulds and threw them in the garden.
Even though they could only amplify his hearing slightly, those early aids kept his hearing nerve alive.
Little did his parents know how much their persistence would pay off, half a century later.
Peter is still a proud member of the deaf community, and like most of his friends uses sign language at lightning speed.
For the first time in his life, he has the best of both worlds.