“It’s so good to hear the sound of your voice.” When talking to an old friend, it’s our natural response. William Shakespeare reminds us in “Love’s Labour’s Lost” that, “A lover's ear will hear the lowest sound.”
Sounds have a deep impact on our emotions and offer a wide spectrum of influences, as they can be loud, soft, interesting, annoying, important, distracting, soothing, infuriating.
Like electricity, gravity and air, sound is a powerful force. Yet, because it is invisible, we often remain largely unaware of the powerful influence sound has on our lives. Still, we have tools to protect and maximize its power.
A recent Centers for Disease Control study analyzing causes of noise-induced hearing loss, along with other recent studies about noise pollution due to environmental projects such as fracking, or the effects of loud city living on developing dementia, expose and remind us of the urgent and ongoing dangers of noise.
But sound is also crucial to our brain development in a positive way. There is ample evidence that playing an instrument has a positive impacton the developing brain. Speaking two languages, another form of sound enrichment, is good for attentional skills and multitasking and may prevent the onset of dementia.
Despite the power of sound in our lives, sound has a certain inscrutability. Due in part to its fleeting nature and its invisibility, we don’t often stop to think about its impact on our brain. Its invisibility also causes us to struggle to describe sounds in contrast to the richly descriptive language we have at our disposal for the things we see.
Seen objects are tangible and persistent. In many cases, we can study them for as long as we like. Unless it is a moving object or an ephemeral action, we can use our eyes to analyze an object’s size, color, texture, and shape, without having to rush.
We have concrete terms we can use to easily convey visual attributes using familiar language. If I used the words small, yellow, fuzzy, and spherical to describe an object, you might guess that the object was a tennis ball, or at least something that closely resembles a tennis ball.
A sound, by nature, though, is never static. It is always moving and so much tougher to describe. I might describe a sound as loud, high-pitched, and dissonant, and while it gives you a global sense of the sound, you wouldn’t be able to begin to guess what I was describing. Is it a siren? A snatch of music? Squealing brakes? A bird squawking?
Nevertheless, our ears and, in particular, our brains do an amazing job of making sense of sound. By some measures, the auditory system is the most computationally intensive neural network. This is particularly true in terms of timing.
No other sensory system, vision included, can compare to the speed at which the auditory system processes the incoming soundscape. Much of this need for speed is due to the simple fact that sounds change over time.
Consider speech. The smallest acoustic unit of speech is a phoneme. For instance, the word “stream” has only one syllable, but it has five discrete phonemes. Change any one of them and the meaning is changed (street) or lost (spream).