A book that explains everything about sound

You can look at a photograph or video image and scrutinize every detail, but sound never stands still. Sound moves through time, so we can only catch fleeting glances of it. Trevor Cox is an acoustics engineer and his "The Sound Book: The Science of the Sonic Wonders of the World" unravels some of the mysteries. Cox doesn't focus on recorded sound or audio gear; no, he's just trying to make us more aware of sound, and when you start really thinking about it the more you'll want to listen.

Cox is an acoustic ecologist, always listening for interesting sounds that surround us in everyday life: jackhammers, waterfalls, church bells, birds, wind, echoes, or engine noises. Cox devotes an entire chapter to reverberation, the sound that fills a room or any space after the initial source of the sound has stopped. Clap your hands once in a large empty room and the sound reflections may continue to reverberate for a few seconds. Some architects, at least the ones who think about sound, try to create spaces with controlled reverberation that make it easier to understand speech.

The best concert halls' sound signatures are defined by the quality and quantity of their reverberation. That's how we hear the "space" of even quiet rooms; blind people can easily gauge the size of the room they're in, just by listening to its sound. Recorded music uses artificial or naturally occurring reverberation to make us feel like the music was performed in a large space.

For the bulk of the book Cox describes sounds he's heard all over the world; the pages read like a sonic tour guide. He's in the Horseshoe Canyon in Utah talking about the rhythmic echoes of the horses' feet, or the "singing sands" in the Mojave Desert. I've never been in a desert, but now that I've read about the coordinated motion of sand grains that produce distinct notes you can sing along with, I'm intrigued.

Cox also visited the quietest place on Earth, the Orfield Laboratories' anechoic chamber. If you've never heard the complete absence of noise, it's really startling. The smallest breaths seems surprisingly loud; your brain has to recalculate. the chamber is so quiet it throws all of your senses out of kilter.

"The Sound Book: The Science of the Sonic Wonders of the World" may not have been written for audiophiles, but I'm sure they will delight in Cox's observations about the beauty of sound. You can listen to some of Trevor Cox's recordings on his SoundCloud page.