• Dogs can hear similar frequencies in the mid range, but MUCH higher frequencies in the top end
• Dogs can hear the higher frequencies at much lower volume
• Dogs ear canal and shape of the outer ear help amplify the sound. Their ability to swivel their ears also enables them to locate sounds with much more precision.

The highly attuned hearing capability goes back to the domestic dogs recent evolution from the wolf. Their recent ancestor hunted in packs but relied mostly on scent for tracking and sound to locate prey animals in the distance. While the wolf is nocturnal, and its night vision is exceptional, it still requires a straight line of sight to its prey.

Human hearing range

Humans can hear sounds approximately within the frequencies of 20 Hz and 20,000 Hz. While this may sound impressive, this is the maximum value that the youngest (best) ears can hear, and even then these frequencies are often quoted for -3dB levels. To the non technical this means at the end of the ranges, people hear sound at approximately half the volume of the central frequencies. This is not such an issue for humans since frequencies below 20 Hz are often felt more than heard, and human speech and many sounds occur above 300 Hz and below 10 KHz.

Human hearing loss

To give an indication of how human hearing can vary with age, the graph below shows how the high frequencies in particular drop off as we age. The graph legend represents the typical hearing ability at the given ages. With a drop of 3 dB representing a loss of half volume, and 6 db the volume being one quarter, you can easily see that even by ten years of age our hearing has dramatically decreased from what it was at birth.

Dogs frequency range of hearing

The frequency range of domestic dog hearing is approximately 40 Hz to 60,000 Hz. This varies with breed of dog and its age. (ref 1) Both humans and dogs can begin to go deaf as they become older, which for a wild dog would severely lower its likelihood of surviving.

The graph below (ref 3) demonstrates how a ‘typical’ dogs hearing differs in both threshold of hearing and frequency. As you can see, a dogs hearing appears to have a higher and sharper threshold profile than humans. Though you need to be aware that frequency ranges are usually reported in logarithmic scales – meaning that the horizontal distance between 100 Hz and 1,000 Hz is the same as between 1,000 Hz and 10,000 Hz.

This shows that while many dogs can not specifically hear as low as humans, the low end frequency difference may only be a matter of tens of hertz – eg human bottom end of 100 hertz versus dogs 200 Hz. And of course dogs are very sensitive to ground vibration so even if they can not hear a very low frequency sound, they can still sense it. The upper frequency difference shows where dogs really excel, with the best of human hearing topping out at 20,000 Hz and some dogs hearing up to 60,000 Hz.

HOW DIFFERENT DOG BREEDS HEAR

The graph below compares how different dogs hear. While this study used only used five dog breeds it is interesting to see how the different type and size of dogs responded to sounds. Also note that while the lower and mid frequencies vary considerably (allowing for the logarithmic scale), that all breeds appear to bunch up in the higher frequencies.

Curve 1 was from the Lipman study (11 dogs non specific breed, audiogram averaged), while curve 2 (Poodle), curve 3 (Dachshund), curve 4 (Saint Bernard) and curve 5 (Chihuahua) were from the Heffner study (1983).

The following table shows approximate hearing range for different species using data from studies by Fay (1988) and Warfield (1973). It is stressed that as the experiment guidelines differed the table should be considered as a rough guide only.

CONCLUSIONS

While a dogs hearing may only seem shifted to the higher frequency range, there is much more to their ability to hear than a simple graph. As dogs live in the moment, they do not have their thoughts cluttered by past and future events, so they can concentrate fully on what is happening around them.

This coupled with the ability to quickly swivel their heads back and forwards while cupping their ears means not only are they more likely to be aware of a sound in the first place, they are also much more likely to pin point the direction and possibly the distance to the source.

Article by Bruce Dwyer. If you wish to use any of this information please refer to the article as a reference and provide a link to http://www.dogwalkersmelbourne.com.au

References

Ref 1  http://hypertextbook.com/facts/2003/TimCondon.shtml

Ref  2 http://www.lsu.edu/deafness/HearingRange.html

Ref 3 http://www.acoustics.org/press/153rd/dooling.html