Timothy P. Walker
Blackpoll Warblers sing in a narrow range above 7 kHz. Photograph by "WarblerLady." (CC BY-ND 2.0.
In June of 2019, my wife Nancy and I attended the Rangeley Lakes Birding Festival in Maine. One of the highlights was a guided drive up a logging road to search for breeding Blackpoll Warblers. Nancy was the first, and only, member of our group to hear them singing on territory. Our guide, a local wildlife biologist specializing in this bird, was not convinced they were present until Nancy caught them in her scope with their mouths open, singing away. It was a sobering moment as our guide came to grips with the reality of his hearing loss. It was cold comfort knowing I was not the only one of a "certain age" who had lost my high frequency hearing range.
On our drive back to Massachusetts, Nancy and I had a talk about how to solve this widespread problem. Surely, we thought, there had to be a solution for a problem that afflicted so many older birders. Could hearing aids be the solution? It was worth a shot, so I made an appointment with an audiologist. Though Medicare does not cover hearing aids, some supplemental plans do, such as Tufts, and, depending on your plan, Blue Cross/Blue Shield may provide generous coverage. It doesn't hurt to check.
My hearing test produced a frequency response diagram of my ears which compared loudness—from loud to soft sounds—to pitch frequency, which is measured in kilohertz (kHz). Typically, you would like to see a straight, horizontal line across the graph. Mine, however, showed a dip, indicating hearing loss, at the higher frequencies. A hearing aid can be used to fill these dips by amplifying high frequencies. Some more expensive models will even shift high frequencies down into the range that one can hear.
Many birds have songs that cover a wide range of frequencies, so, even if you may not hear the whole song, at least you can hear a portion. Some birds, however, such as Blackpoll and Magnolia warblers, have songs with a narrow range. If you have lost hearing above 7 kHz, then you will not hear these birds sing. If you can identify songs you have difficulty hearing, you can use those songs to test your hearing aids.
Maybe you are thinking that hearing aids are a bit extreme for your situation. A theoretical solution could be a directional microphone, to filter out noise not in the direction of the song, paired with a headset and a graphic equalizer, to boost high frequencies. I tried this approach with a Rode VideoMic and Apple earbuds paired with an iPhone Xr. The hardware appeared to work, but there was no way to feed it through an app as the earbuds had to connect directly to the microphone. I did not try Bluetooth earbuds or every graphic equalizer app, so a solution to this problem could be out there.
A few fellow birders in similar circumstances shared their solutions. Dennis Skillman uses Walker's Game Ear(s) when birding. He recommended the models with two earpieces for easier location of the bird. He has two HD Elite models. Another birder reported that Bose Hearphones (that's the actual name) work well for hearing birdsong. They go for about $500.
Most people think that hearing aids are expensive and you need an audiologist to buy one. That is not true. Devices called PSAPs (Personal Sound Amplification Products) can be bought by consumers, without the need of an audiologist. I bought a pair for $200 from Olive Union (https://www.olive.store/en/), a start-up in Korea that was funded by Kickstarter. The Olive devices come with an iPhone app that lets you do your own hearing test and then programs the devices using the results of the test. The device also allows you to boost the high frequencies.
I took my new Olives to Crooked Pond in Boxford for a trial run. Unfortunately, I couldn't detect any difference. These devices automatically carry out noise reduction in order to enhance voice recognition. So what do they make of a bird call? They think it is noise. For the Olives I bought, noise reduction could not be turned off, though the manufacturer plans to include that feature in a later release. If you search the web for "PSAP hearing aid" you will find many devices. Birders, however, need one without noise reduction.
Because my hearing test produced that dip at higher frequencies, I was eligible for hearing aid coverage through my health plan. I then set about finding the optimum hearing aid for my situation. There are several manufacturers of high-end hearing aids and most audiologists will carry more than one brand. Their goal is to help you pick one that works best for you. However, because a birder's criteria are different from a normal consumer, it is difficult to find an audiologist with the appropriate experience. My first experience with an audiologist was not successful, as they were not interested in understanding my needs.
I next tried a place in Newburyport, hoping they would have experience with birders. I found a very enthusiastic audiologist, however the brand they sold, Resound, had only three adjustable frequency bands. When the audiologist tried to compensate for my dip, the added gain caused unwanted feedback.
I then went looking for a brand with more frequency bands and I discovered the Signia Styletto. It had 48 channels., which was twice as many as another device by Phonak. The Signia receiver bandwidth also went beyond 10 kHz, whereas the Phonak barely got to 8 kHz. More importantly, I found an audiologist in North Andover who was interested in my problem. She even had me meet the Signia sales representative. The lesson is that most audiologists do not understand birdsong, so one needs to shop around for one who does.
To test my new hearing aids, I bought a sound pressure meter with a bandwidth greater than 10 kHz to calibrate my measurements. I used the Sibley Bird App V2 on my iPhone Xs to generate the songs, choosing the first song for each species. I went outside and set the iPhone song volume at 90 dBa and then measured how far away I could still hear the song.
The following is a table of the distances at which I could hear different songs with and without the hearing aid.
||Distance (ft) with no hearing aid
||Distance (ft) with Signia hearing aid
|Black-throated Green Warbler
|Cape May Warbler
I was very happy with my results. I found it was possible to get a five-fold to ten-fold improvement in hearing birdsong. The Signia Styletto is rechargeable and can hold a charge for three days. I keep it in my car plugged into a USB port so it is always ready when I decide to go birding.
Based on my experience, my recommendations to birders looking for similar results are as follows:
- Check your insurance to see what they will pay and if there are in-network providers.
- Get a professional hearing test.
- If insurance won't pay very much, then go to Costco. If insurance will pay a good portion, then consider a local shop carrying one of the major manufacturers.
- Pick out birdsong that you have a hard time hearing, so you can show the audiologist what you want to hear.
- When selecting a hearing aid, look for the ability to turn OFF all noise canceling. As far as I'm concerned, this is the number one feature. I wouldn't consider any aid that you cannot turn off noise canceling.
- To cover the range of most birdsong, be sure that the receiver bandwidth extends to >10 kHz.
- Determine if the aid can work as a directional microphone. This feature might be useful when trying to listen in a marsh.
- Determine if the aid can shift high frequencies to a lower band. This feature could be useful if you have significant high-frequency loss.
Also, most of the cost of the hearing aid is dealing with noise reduction for voice. So, if you can hold a conversation, you should be able to use the low-end of most hearing aids.
With all the technology out there, things are constantly changing but this account will give you a good idea of my process. I'm happy to answer further questions at my email address below. Here's hoping you will hear those birds you thought were lost to time.
Cooling, Geoffrey. 2019. The Little Book of Hearing Aids 2019: The Only Hearing Aid Book You'll Ever Need. Independently published. (This book is available as an e-book or paperback from Amazon. I found it well worth the money. The author even responded to my questions. There is a new edition for 2020.)
These websites have useful information:
Timothy P. Walker is an electrical engineer by training. He has been birding since 1985, when he wanted to know what was coming to his feeders. Since then, he has birded all over the United States and even out of the country. Tim and his wife Nancy live in West Boxford, Massachusetts. His current obsession is birding Essex County with his wife. He can be reached at firstname.lastname@example.org.