Have you ever noticed how many elderly folks tend to need hearing aids or ask you to speak louder so they can hear you? – This is because a person’s sense of hearing deteriorates as they get older. Some people are affected more than others, depending on their lifestyle.
Image Credit: LubosHouska/Pixabay
The sensory cells inside your ears wear out after trauma sustained from years of use; by the time you turn 65 years old, your hearing sense may lose up to 30 dB in sensitivity to higher sound frequencies.
Humans can’t regenerate these sensory cells after trauma, so our overall sense of hearing takes a hit when they wear out over time. On the other hand, some bird species retain their crisp auditory sense as they age because they can regenerate these sensory cells as needed.
The European starlight is just one bird species known to have 'ageless ears,' and a group of researchers led by Dr. Ulrike Langemann from the University of Oldenburg sought to find out whether the same was true in barn owls.
After gathering seven barn owls ranging from 2-17 years of age, the researchers commenced with sound testing to answer their pressing question. They've published their results in the Proceedings of the Royal Society B.
Just as you would train a dog to expect a treat after performing a trick, the researchers taught the seven barn owls to wait for a treat after flying from one position to another. They were trained to take flight only after hearing an auditory signal, after which they would fly to another perch and obtain a treat if successful.
The owls were grouped based on their age as a control, and the researchers tinkered with the sound frequencies to see how each age group reacted to the sound changes. Since barn owls have such acute hearing, the researchers expected to see better performance in the younger ones compared to the older ones.
To the researchers’ surprise, all the test subjects completed the testing with similar results despite the differences in age and changes in the audio frequencies. The results strongly indicate that older barn owls don’t exhibit a noticeable drop in sound perception as expected.
The findings pushed the researchers to test new extremes, so they gathered a 23-year-old barn owl and put it through the same tests. Remarkably, even the eldest barn owl performed just as well in the testing as the younger ones did previously.
The results highlight how some birds can retain their phenomenal hearing as they age, and it’s inspiring to consider what we could potentially learn from them. Further research into the mechanisms behind birds’ sensory cell regeneration may help in treating humans with hearing problems in the future.