Listen out for underwater sounds

Whales and dolphins aren’t the only underwater sounds to listen out for on your swims, try tuning into the rasp of water shifting small stones, the scratch of aquatic insects and even the sound of oxygen bubbles being released by plants as they photosynthesise.

Warm summer waters aren’t just a time and place to get in longer swims. They are also when you might pause and float to listen to sounds underwater. Unless you’ve had problems with water in your ears or ear infections, in which case it’s probably best to keep your ears dry.  

Whale song has made its way into muzak, but there is a lot more to the acoustics of underwater worlds. Dolphins and whales communicate across a range of frequencies, only part of which is within the ability of human hearing. If you were lucky enough to be joined by dolphins you might catch some of their chatter, which sounds like whistles and clicks. 

On a dip with no large animals around, perhaps the first sound to stand out is repetitive noises made by lapping water shifting small stones or the rush of flowing water. After recognising mechanical sounds, you can start tuning in to noises made by wildlife around you that are more irregular. It can be easier to hear wildlife in calm water where the water is less noisy; like ponds, lakes and sheltered bays. In freshwater, in the evening or early in the morning, there are noises that sound like scratching, these are made by aquatic insects. In daytime sunshine you might be surprised to find out that ticking and whining noises are the sound of oxygen bubbles being released by plants as they photosynthesise.