Paul Lehman once joked that after he reached a certain age, Grasshopper Sparrows no longer sang, they just yawned.
Birders tend to notice hearing loss before other people. We’re one of the few groups who care a great deal about hearing faint, high-pitched sounds, like the “tseet” of a distant chickadee that might alert us to the presence of a mixed-species flock of migrants. Many older birders have written about the experience tracking their hearing loss from the high-pitched species gradually down to the low-pitched ones.
I’ve been concerned about my own ears recently. I’m not yet 40, but hearing loss runs in my family, and for the past couple years, it’s become obvious that most of my birding friends can detect a chickadee at twice the distance that I can. For some reason it’s even worse with Blue-gray Gnatcatchers — I can’t hear them at all anymore if they’re more than 75 yards away.
For my whole life, my right ear’s been much worse than my left. Even as a child I could only answer the phone with my left ear, and sleeping on my left side has always been a natural way of turning down the volume in the bedroom. But in the past few weeks, I started noticing that my “good” ear was deteriorating considerably. When I put my headphones on to listen to a recording, the right ear sounded louder. My fiancee started commenting that I was having more and more trouble hearing what she was saying when we were in public places.
So, today, she finally convinced me to go to the audiologist.
Half a second after looking in my left ear, he declared, “you have a massive buildup of earwax in there.” With a tiny scoop, he pulled out a disgusting black glob the size and shape of an earplug. I had no idea it was there, and it didn’t even hurt to remove, but the improvement in my hearing was immediate. According to the audiologist, a buildup like this can happen to anybody, at any time. It’s just one of those things.
He proceeded to screen my ears in the usual way. It turns out that I do have high-pitched hearing loss, but without the homemade earplug, it’s not that bad yet. Right now I’m only a borderline candidate for a hearing aid. He said that unless it started really bothering me, I could come back in for another checkup in five years. Music to my (newly restored) ears.
An email from Denise Wight alerted me to the Spectrogram application for the iPhone, which is a pretty neat little app indeed. It uses the iPhone’s built-in microphone to create realtime scrolling spectrograms of any sound you’re hearing. This means you can see spectrograms in the field, at the very same time that you’re listening to the bird sound.
Why is this exciting? Because now those with hearing loss can see the sounds that their ears can’t hear!
Here’s an example. Ted Floyd, editor of Birding magazine and author of the Smithsonian Guide to Birds, is Colorado’s recognized guru of nocturnal migration study. Ted and I have gone out together many times to listen to nocturnal migrants giving their quiet “seep” and “tsit” notes high overhead in the dark, and every experience has been frustrating for me, because Ted invariably hears ten times more flight calls than I do, and that’s no exaggeration. My ears simply aren’t good enough to register such high-pitched sounds at such low volume. I can only hear the lowest, loudest migrants, and for a while I suspected Ted might be making up the rest.
No such luck. I realized the phantom flight calls were real when I carted my laptop into the field, plugged my shotgun microphone into it, and started recording with Raven. Voila: a realtime scrolling spectrogram showed me the sounds of the night sky, even the ones I couldn’t hear. The scrolling spectrogram gave me a chance to identify sounds visually that I couldn’t even detect by ear.
Now anyone with an iPhone can have the same experience, for the low price of $4.99, without having to lug a laptop and a microphone into the field.
The Spectrogram application has its pros and cons. The gain is adjustable, which is nice. You can adjust the frequency scale to run from zero to 8 kHz, 22 kHz, or 44 kHz — the 8 kHz setting should work best for most bird sounds — but you can’t zoom in or out on the time scale, which means those flight calls aren’t likely to be visually identifiable. This may be better in future versions.
One thing that drives me absolutely nuts is the color scheme. You can’t change it to grayscale — you’re stuck in the odd red-and-blue mode. Personally, I can’t stand spectrograms in colors. They may be nice for other purposes, but when it comes to identifying bird sounds, the colors get in the way. Birders don’t need much information about loudness; for us, a spectrogram is text, and it’s meant to be read. Therefore it needs to be in black and white, for the same reason that books need to be printed in black and white — anything else hurts the eyes after a while.
I could say more, but I’ll dismount my soapbox. Before signing off I should note that Pete Schwamb, the creator of Spectrogram for the iPhone, has also created a couple of other cool audio-related iPhone apps — including CricketSong, which uses the chirping of Snowy Tree Crickets to determine the air temperature. Check it out.
In honor of Earbirding’s first birthday (yes, we went live one year ago today), I’m posting on the topic of getting older — and losing your hearing as you age.
Age-related hearing loss, or presbycusis, happens to almost everyone to some degree, although it tends to be more severe among men, and susceptibility can run in families. It runs in my family, for better or for worse — even though I’m not yet 35, when I go birding with my friend Walter, he can detect chickadees by ear at twice the distance at which I can hear them. The other day, he and I watched a Blue-gray Gnatcatcher vocalizing at a distance of about 50 meters. He could hear it distinctly; I watched the bird’s bill opening and closing in silence.
Age-related hearing loss tends to affect high frequencies first, so that the upper frequency limit of a person’s hearing tends to decrease over time. A European inventor exploited this fact to create a device called “the Mosquito,” a type of sonic “youth repellent” that keeps bus stations and storefronts free of loitering juvenile delinquents by emitting a piercing high-pitched frequency that only young people can hear. (In retaliation, young people have converted the “Mosquito’s” buzz into a cell phone ringtone that their aging teachers can’t hear when it rings in class.)
In the past I’ve written about some corrective technologies for birding by ear. Today I’d like to give those of you with perfect ears a chance to experience partial hearing loss. It’s easy to filter out the high frequencies of bird sounds to get an idea of what you would hear if they were missing. Some songs, like those of the Golden-crowned Kinglet, would disappear entirely. Click on the link to test your hearing — if you can still hear the kinglet’s song, then your ears are pretty good. I can still hear high-pitched songs like this just fine, as long as they are at close range.
But there are other ways that hearing loss can affect our perception of sounds besides eliminating the songs entirely.
Losing Songs in Pieces
Some bird sounds are composed of both high- and low-pitched notes, so that those with presbycusis may hear parts of the sound and not others. A great example is the typical “fee-bee, fee-bay” song of the Carolina Chickadee, which is one of the best ways to distinguish it from the lookalike Black-capped Chickadee, which sings a simple “fee bee.” The complete song is easy to identify:
But those with an upper hearing threshold of 6 kHz, which constitutes only a moderate hearing loss, will hear just the two lower notes:
And that makes it sound much more like the Black-capped Chickadee:
Hearing Loss and Tone Quality
I used to be skeptical that presbycusis could affect the tone quality of sounds, but in some cases it can, especially if the sound is highly nasal.
Here’s a quick reminder in case it’s been a while since you visited the page that explains the nasality of sounds. To have a nasal tone quality, a sound must be harmonically complex. Such sounds appear on the spectrogram as vertical stacks of lines. If the darkest lines in the stack are at the bottom, the quality of the sound won’t be nasal at all. The higher the darkness climbs, the more nasal the sound. Thus, the call of the California Gnatcatcher sounds intensely nasal:
Here’s the same sound, filtered above 6 kHz. Note that the basic sound remains the same, but the quality changes slightly. However, I’d still call it “nasal.”
Here’s the sound filtered about 3.5 kHz. (This is about the same level of high-frequency filtering forced on all of us by our telephones. If you’ve ever wondered why people’s voices sound slightly different over the phone, it’s because the phone companies decided long ago that those higher pitches were mostly unnecessary to human speech, so they simply aren’t transmitted.) This version of the call maintains its basic pitch (because pitch is determined by the spacing between the partials), but the quality is muted, duller, and less nasal.
I know I said I’d be gone for a couple more weeks, but that was before I got this great guest post by Mel Goff reviewing the SongFinder by Nature Sound Electronics, a device intended to help birders with high-frequency hearing loss. As I suffer a little bit from that malady already (and will likely suffer much more in years to come), this is a topic of great interest to me, and I hope others will benefit from Mel’s review.
One thing Mel wanted me to mention was that he has no vested interest in the product or the company; he just thinks this information needs to get out. With that, I’ll turn it over to him (and sign off again until March, as planned):
by Mel Goff
I am 64 years old and have high frequency hearing loss. I spent 21 years in the US Army and the noise levels from computers, heavy equipment and weapons did me no favors. I have been birding with my wife, Jeanne, since a trip we took to the Everglades National Park in 2002. We make quite a team as she can hear the birds and I can do a pretty good job of spotting them. I tried all the latest and greatest hearing aids, and while they amplified the sounds that were within my frequency range, they did nothing to let me hear the sounds from the higher frequencies where the majority of birdies tweet. I could never justify the cost of those hearing aids when they did not do the one thing I wanted from them.
Then I saw an ad in the ABA’s “Birding” magazine for a product called SongFinder. It alluded to its ability to digitally convert high frequency sounds to lower frequencies thus enabling people like me to once again hear the birds.
Let’s Check It Out
With some optimism and much skepticism, Jeanne and I went into the home office and opened the Nature Sound Electronics webpage at www.nselec.com. I went from page to page reading about the frequency shifting technology, the testimonials, and the ordering information, until I finally came to the “Sound Samples” link. On this page there are pictures of 16 birds that I had long ago decided were mute. After all, I could hear a crow, so why couldn’t I hear a Yellow Warbler? I clicked first on that YW and a voice said “Yellow Warbler” followed by silence. Jeanne said, “Yep, that’s the Yellow Warbler.” Then the voice said “Divide by two”. Oh, my gosh, I heard it! It’s a trick! It cannot be!
We listened to all 16 with the song divided by 2, 3, and 4. Jeanne assured me that the “divide by 2” option was by far the closest to the real song. The others had the same pattern and cadence, but the lower pitch came off as less than satisfactory.
Let’s Give It a Tryout
Seeing that there was a 14-day refund policy, I decided to give the SongFinder a tryout. The only problem was that this was Monday, and we were leaving for Hawaii on Saturday. I called the company and I agreed to pay for FedEx second-day delivery. I got the unit on Friday afternoon, just 12 hours before we had to head for the airport.
On the plane I read the manual, then re-read the manual, then read it one more time. When we arrived in Lihue, Kauai, we had to get a rental car, buy groceries, drive to the resort, check-in, unpack – well, you get the picture. By now it was dark and the birds had retired for the evening.
The Big Day
Sunday morning, just after sunrise. We are dressed, we have our binocs and guides, and we head out to test the SongFinder for the first time.
At this point I want to tell you that the online demo did nothing to prepare me for the symphony of sound I would hear when we stepped into the resort parking lot. Cardinals (Northern and Red-crested), Japanese White-eyes, White-rumped Shamas, House Sparrows, House Finches, and Common Mynas all performed just for me. I could not believe what I was hearing! In fact, I decided to turn off the switch to see what would happen. When I did, all I could hear were the Zebra Doves, Spotted Doves, and Junglefowl that I had heard on our last visit to Kauai.
I am not ashamed to say that when I turned the power back on, I shed a tear or two as the concerto of songbirds once again came through the headphones. I was now finally a BIRDER, not just a Bird Watcher. For the next 16 days on Kauai, Maui, and Oahu, I heard the calls and songs of 76 species – seven of them lifers for Jeanne and me. The endemics: I’iwi, Apapane, Amakihi, and Maui Creeper at Hosmer Grove. The Japanese Bush-warbler on Lower Koke’e Road. The Bulbuls and Shamas at Lyon Arboretum. I cannot begin to describe the feelings I had.
The unit is easy to set up and use. It is lightweight, and clips to my belt. The size of the unit (4″ by 8″) did not bother me in the least. Adjustments for volume and frequency were easy to make. I used just the first 4 AA batteries I installed for the full 16 days and did not have to replace them even though I did have backups with me.
The SongFinder does not change any of the sounds I can already hear. I still hear the doves and crows and jays and flickers just as I did before. Their songs and calls do not come through the headset and are not altered. That is an important fact, because directionality will be mentioned in the next section and SongFinder does not affect that for the birds I just mentioned.
Herb at Nature Sound Electronics worked with me to get the unit delivered before I left, and even told me that if I had a problem with the unit, he would not be too strict on the 14 day policy since I told him our plans in advance.
In actuality, there is no “Bad”, but there are a couple of things I should mention. Directionality is not a strength of SongFinder. It lets me hear the birds, but it is not Full Surround Sound Stereo that would let me pinpoint birds. Jeanne still helps me with that. Also, birds that are far away still sound far away. The unit is a frequency converter, not an amplifier.
I wear a large hat, size 7 & 7/8. The SongFinder headset is not adjustable like music headsets, so the one-size-fits-all idea is actually one-size-fits-most. It takes getting used to, but is something I gladly will adjust to. I plan to try to find a way to adjust the headset or see if the company has a larger model.
The cost may put off some folks. At $750 plus $15 shipping, you may think it is too expensive. But let me tell you that it is a small price to pay for the benefits you will receive. Digital hearing aids that will do nothing to let you hear the birds can cost five times as much.
SongFinder has changed my birding life. I can’t wait to get out in the mornings to hear the sounds of the winter birds. The chickadees, juncos, sparrows, finches, and Downies are beautiful to see, but even more beautiful when you can also hear them. I cannot speak to long-term reliability, but first results have been overwhelmingly positive. I wholeheartedly recommend SongFinder to any birder with high frequency hearing loss.