Fun Fact: A dog's sense of hearing is 4 times greater than humans!
Aside from a dog's super-smell power, hearing is their second most powerful sense. Dogs have a frequency range that is double that of the human ear. That is why we notice our dogs being alert to sound seconds or even minutes before you can hear the same sound. On the downside, loud and abrupt noises that may be totally normal to our ears can prove to be very uncomfortable to our canine companions. A lot of dogs grow super agitated and timid during thunderstorms - and this is why.
Dogs have roughly 18 working muscles in their ear allowing them to rotate, raise, lower and tilt them in many different directions. They are able to move their ears around with a tremendous level of flexibility, playing a huge role in their ability to focus on exactly where a specific noise is coming from.
Unlike humans, dogs also have the ability to hear two different sounds at one time, one sound in each ear. So the next time you think your pup is ignoring you, remember that they are probably listening to you and another sound, they are just more interested in what they are hearing with the other ear.
Source (Image): Bright Mags