Ping ping ping. That's the heat circulating through the baseboards. Vents. Whatever you call them.
Bling bling bling. That's my son strumming some chords on his guitar.
If you listen carefully there are sounds emanating from various places all throughout your house. We're visual people, most of us, noticing the things we can see with our eyes, except when we're not really paying attention. And when it comes to smells, well, the rankest ones hit us right in the nostrils, commanding our attention. But the sounds.? Not always so obvious. Much more subtle. But they're there. Close your eyes and listen.
Even when you think a house is silent, it really isn't.