Turn Your Phone into a Bat Detector with the Echo Meter Touch 2

 Did you know that the bats flying above you at dusk are shouting as loud as a fire alarm in your ear but you can’t hear them? That’s because they’re calling in frequencies that are too high for your ears to detect. But now, with an incredible little bat detector that plugs into your phone, along with a bat detector app, you can hear bat echolocations in real time, record them, and identify the species! It’s time to get a new super power. Meet the Echo Meter Touch 2 bat detector.

Bats have an incredible skill. They can use sonar to navigate in the dark and to catch tiny insects on the wing. They do this by “shouting” short chirps or clicks into the air and processing the echoes as they bounce back into their ears, known as echolocation. These sounds occur at a pitch that is higher than humans can hear so we refer to it as “ultrasonic”.  But with an ultrasonic microphone and bat recorder, scientists can record and analyze the echolocation calls of different bat species, then learn to identify them by their call.

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Need a Bat book? Check out this Bats of the United States and Canada guide. After you’ve identified your bat, this is a great resource to learn about your batty neighbors.

If you’re a regular person like me who wants to hear bat echolocation calls and learn what species are in your yard, then this is, without a doubt, the coolest wildlife gadget you’ll ever own. With a price tag of only $179 (at time of writing) it is well within the price range of most backyard wildlife enthusiasts. But don’t let the cheap price tag fool you. This little gizmo is packed with sophisticated technology and uses advanced scientific identification software to let you know who you’re listening to. I think it’s a fair price to pay for a super power.

And the best feature in my opinion: it’s tiny. Cristina and I travel frequently to look for wildlife. This little guy sits snuggly in my pocket in a cute little pouch and is ready for action as soon as the sun sets.

This bat detector app is packed with amazing features, but you don’t have to be an expert to use it. I was up and running in seconds, listening to bats, recording them, and identifying them without, I admit, ever reading the manual. Thankfully they have an excellent collection of tutorial videos and you only have to watch the quick start video to do most everything you’d ever want to do.

You can also download a free version of their Kaleidoscope analysis software and use it on your desktop or laptop (Mac, PC, or Linux) to view the spectrograms and listen to recordings of bats and other animals like birds and frogs. 

According to a recent email, Apple has discontinued the lightning connector that Wildlife Acoustics uses to connect the Echo Meter Touch to Apple devices. They’ve already sold out the Echo Meter Touch 2 for iOS and expect to sell out of the Echo Meter Touch 2 Pro for iOS by the end of 2022. Hopefully they will find a new solution soon to continue providing an iPhone bat detector option. In the meantime the bat detector for Android is still available. However, I did just notice that the Android EMT 2 was “sold out for the season” while EMT2 Pro was still in stock at $349. 

(Full disclosure: I was given this bat detector in exchange for a review but all of the opinions in this article are entirely my own. Yep, I got Cristina’s birthday present for free and then mostly used it myself. Am I cheap or what?)

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We built our bat house, but you don’t have to! You can get your bat house here. But if you want to build one yourself, this bat house guide will help you.

In our region (North Carolina mountains in the United States) bats hibernate in the winter because there are few insects around. But on warm days they may ‘wake up’ for short periods and became chatty with their neighbors. These social sounds are mostly within the range of human hearing. That’s what we could hear coming from the bat house. 

I managed to get some photos of them with both my phone and a DSLR camera by carefully pointing them up through the bottom opening of the bat house. We had at least three and possibly four in there! But I had little confidence in my bat identification skills so I had no idea who our new friends were.  That’s when we started searching for a bat detector.

The problem is that a bat recorder like the Echo Meter Touch 2 identifies species using ultrasonic echolocation calls that are made while flying and hunting. And ours wouldn’t be flying for months until the insects returned. So we had to wait until the days got warmer before we could try it out.

Because my charge port is on the bottom of my phone, I had to flip my phone over to point the microphone toward the bat house. Since apps can’t flip upside-down on my phone, I had to view the screen sideways in order to watch the color spectrogram rolling by. I selected North Carolina from the Auto ID Selection menu so it would only choose species likely to be in my area, and I chose the RTE setting for audio (Real Time Expansion) so I could listen to the pulses in real time.  Then I  turned up the volume on my phone and listened.

The spring peepers were calling loudly from our pond, but hearing their high pitched calls through the app came out only as very low thuds. Then, 15 minutes after the official time of sunset, I heard it. Not with my ears but through the phone.

A series of sharp, descending chirps, repeated in clusters. Someone was preparing to exit the box! I hit the manual recording button (which starts recording 5 seconds in the past so you don’t miss anything) and looked up. The chirps became louder and faster and then, right before my eyes, a bat descended from the box and swooped up over my head into the gloomy dusk. Woo hoo! 

To my ears the bat had been totally silent, but through the app I could tell she was echolocating like crazy as she left the house and, in reality, was shouting quite loudly! I was thrilled and smiling from ear to ear.

When I tapped the info button, a portrait of the creature filled my screen. She had shaggy reddish brown fur coming down a deep forehead to an otter-like nose and a wide smile. Large black ears protruded above her twinkling eyes. There you are, my little friend. Nice to meet you!

Another tab took me to the wikipedia page for the species. There I learned that the big brown bat, as the name implies, is pretty big for a microbat, with a wingspan of more than 12 inches! I also learned that the big brown bat thankfully appears to be somewhat resistant to the effects of the devastating white-nose syndrome that is wiping out bat populations across the United States.

For many nights I recorded the bats leaving their bat house. Every time I received the same ID so I felt pretty confident in the accuracy of the identification. (See later section: How accurate are bat identifications?). But it was the only species I could find near my house. I wanted to try it out in other locations and start building my species list!

In early May when I had finally completed my Covid vaccination shots my mom and I did a cross-country road trip from NC to California and back for my nephew’s wedding. I tried it at Juniper Campground in Bandelier National Monument in New Mexico. The first two identifications gave me northern long-eared myotis (Myotis septentrionalis) and my next seven came up as western small-footed bats (Myotis ciliolabrum)  so either I had two species flying through or, more likely, the first 2 recordings were mis-identifications.

In Barstow, California I picked up western pipistrelle (Parastrellus hesperus) from a Super 8 parking lot.  Cool!

In late May we made a run to Tennessee to see the glow worm caves in Pickett State Park. While staying in one of the adorable stone cabins built by the CCC, I detected a silver-haired bat (Lasionycteris noctivagans) flying nearby.

And then in early June on a quick trip to Raleigh, NC I had a mysterious clump of five different identifications in one 10-minute period. Here is my list of ID’s followed by the accuracy rating (Correct Classification Rate) for each species according to the Classifier Performance Table.

Based on the accuracy rates, I concluded that it was simply my first experience with a species that was difficult to identify. In retrospect I should have turned the Auto ID Sensitivity setting from Sensitive to Accurate and might have had better luck getting the right ID. (See the section How accurate are the bat identifications? below) 

Wildlife Acoustics is a big name in the world of wildlife audio research and they’ve built some of the most advanced wildlife sound identification software available. One of Wildlife Acoustics software products is called Kaleidoscope Pro Bat Auto ID. They’ve developed classifiers for 38 bat species in North America, which covers almost every species you’re likely to hear. But they’re also constantly adding to their list of classifiers for other regions of the world. At the time of writing they created classifiers for 37 species in the UK & Europe, 37 Neotropical species, and 21 in South Africa. You can see a complete list of species here.

But the best news is that the Echo Meter Touch 2 uses the exact same database of classifiers in its free app. Though the website says new classifiers may lag a couple weeks behind the Kaleidoscope software so be sure to keep your app updated.

My favorite flying bat photo I’ve ever taken (below) is of a Jamaican fruit-eating bat (Artibeus jamaicensis) which is one of the only fruit-eating bats that occur in the United States (found only in the Florida Keys). But ironically, it is also one of the only species that Kaleidoscope doesn’t yet have a classifier for in the North American list. Even though it’s a fruit eater, it still uses echolocation. Previously thought to be a “whispering bat” it has since been proven that their echolocations are extremely loud! I photographed this one under a Maya ruin in Tikal, Guatemala.

We’re excited to try our bat detector in South Africa because we travel there often. In the photo below you can see a bat flying over Cristina’s head in a chalet in Twee Rivieren in the Kgalagadi Transfrontier Park, South Africa. Next time we’ll identify what species they are!

If you set it to “Sensitive” then you’ll get more identifications but they’ll be less likely to be accurate. Conversely, if you use the “Accurate” setting you’ll get fewer ID’s but you’ll have a much higher accuracy rate. If you want something in between you can choose “Balanced”.

Let’s use North America as an example. Based on the most recent Classifier Performance Table we can see that using the “Sensitive” setting  you’ll receive an accurate ID about 70% of the time on average. However, some species tend to get confused more easily, while others have more distinct echolocation calls. You’ll get an accurate ID about 97% of the time if it’s a Spotted Bat (Euderma maculatum) and only 31% of the time if it’s a Cave Myotis (Myotis velifer).

If you use the “Accurate” setting on the app, you’ll end up with fewer recordings getting an ID, but they’re more likely to be accurate when you do. Now you’ll have an average 82% success ratio of correct ID’s, with several species reaching 100% accuracy.

Keep in mind that the identification software won’t work as well in cluttered spaces (like forests) or when multiple bats are flying overhead. You’ll get the most accurate ID results from a single bat flying over in a more open space.

You can simply hit the record button and Echo Meter Touch 2 will automatically record whenever a bat echolocation is detected! You can choose parameters for recordings to suit your needs.

Share files

It’s really simple to export .wav files to your computer or share them with others. You can email them, text them, airdrop them, etc. or transfer them to your desktop via wifi. You can install the free Kaleidoscope Lite analysis software on your computer to view and analyze your transferred recordings!

GPS view

If your phone or tablet is GPS enabled, the Echo Meter Touch 2 records GPS data for each recording and embeds it in the metadata for that file. In the app you can look at a GPS view to see where all your recordings were made and follow the path you used between recordings!

Label recordings  with text and voice notes

It’s easy to add a note to a recording by typing it or simply recording your voice. I use it to add info about where I recorded it like “Super 8, Barstow, CA”.

Choose different listening modes

I prefer to use the RTE (real time expansion) mode when listening to bats. This basically interprets the sounds into the human range of hearing in real time. You can also choose HET (heterodyne) which is a more old-school way of listening to bat echolocations and I have no clue how to explain it, but it just kind of sounds like clicks.

Finally, when you’re playing back saved recordings, you can use TE (time expansion) which may be the coolest one of all. It basically slows down the recording to one-tenth speed or one-twentieth speed (your choice) which brings it down into the human range of hearing. This way you can really hear the nuances of each pulse, the variations in pitch and speed, and it has an other-worldly haunting sound, sort of like the recordings of whale songs!

And since you made it through that boring section, here’s a cool picture of a bat crossing sign from Calakmul in Mexico! (from my animal crossing signs collection.)

I also noticed on the Wildlife Acoustics FAQ page that the Echo Meter Touch 2 can be used to record ultrasonic mice vocalizations! But you’ll have to adjust a few settings to use it on species other than bats.

If you want to record bird and frog calls then check out the Song Meter Micro. It’s a standalone unit used to record wildlife calls and then you can view and analyze them with the Kaleidoscope software and even create your own classifiers!

Check out the Echo Meter Touch 2 for Android and the Echo Meter Touch 2 Pro for iOS.

(P.S. Here’s a video we made of how to find tent-making bats in Costa Rica!)