The typical hearing response covers a broad range of frequencies. For a healthy young person, this is normally from 20 to 20,000 hertz. Our ability to discern these ranges helps us to hear low rumbling sounds and very highly pitched sounds.
As we age, our ability to hear higher frequency sounds lessens. This is natural and under normal circumstances does not have a great deal of impact. However exposure to loud noise over extended periods of time can cause some hearing loss and have a greater impact than what would normally be expected.
The hearing frequency range which most people can hear is very different than for many other animals. For example, a dog can normally sense sound from 40 Hz to 60,000 Hz.
We are probably familiar with a “silent” dog whistle. It produces sound which is above a frequency that your ears to sense. However, it is still within the range for dogs and is therefore a good way to alert our pets without disturbing other people.
Dogs have specialized muscles in their ears to help train and focus on the sounds which enhances their ability to hear subtle sounds as well as sounds in higher frequency ranges. This is a very useful ability for guard dogs so they can sense the presence of intruders or other unusual sounds.
Bats have incredibly sensitive hearing and can have hearing frequencies which range from 20 Hz to 120,000 Hz. This kind of sensitivity enables them to locate prey by using a process called echolocation.
They create a high pitched sound which bounces off their prey. The bat can discern this sound and interpret the location and type of prey in this way.
So as you can see, the frequency range for a human is not as broad as many animals. Since we humans can use our intelligence to help protect ourselves, it has not been as important that we can sense higher frequency sounds. Nature seems to do a good job and evolve our senses to an optimum level for our environment.
As was indicated earlier, a healthy 20 year old can typically hear frequencies in the range from 20 Hz to 20,000 Hz. The ability to hear higher frequencies does deteriorate over age.
For example, a typical middle aged male can discern upper range frequencies of 12,000 to 14,000 Hz. And the hearing range for men typically worsens faster than for women of the same age.
