If you are using an Android device with the EMT 2 or EMT 2 Pro, you can use Bluetooth headphones or wired headphones to listen to the app's output as you record.
Because of limitations in the way iOS handles audio devices, Bluetooth headphones can only be used with the EMT app if you are using the EMT 1 hardware. If you are using the EMT 2 or EMT 2 Pro hardware, Bluetooth headphones will not work, but headphones connected to a standard 3.5 mm jack will work.
The EMT 1 and EMT 2 Pro can be configured to record sounds above 8 kHz other than bat echolocation pulses, such as mice vocalizations. Because the EMT settings are tuned by default to automatically record bats, a few settings changes are necessary.
In the advanced settings pane, turn "Real-Time Auto ID" off to prevent the app from trying to assign a bat species to your recordings. Turn "Save Noise Files" on so that recordings will be kept regardless of if the app thinks it recorded a bat or not.
When you are in live mode, using the manual record button to create continuous recordings may be more useful than using the automatic, triggered recording mode, which is tuned for bats and may perform ideally with non-bat vocalizations.
The Echo Meter Touch does log the recording location if you have an iOS or Android device that includes GPS functionality. Any device that is GPS-enabled will log both GPS locations and path. If your device does not have a built-in GPS, you can purchase a Bluetooth GPS module that will stream location data to the iOS or Android device. There are several such devices on the market, including the Dual Electronics XGPS150A and the Garmin GLO. Both are under $100, highly accurate and have their own batteries to avoid depleting the iOS or Android device. If you have built-in or Bluetooth GPS, then all the recordings will be tagged with their location and the path will be recorded from each recording session. The path and locations are also exported with recordings in KML format and can be opened in Google Earth.
The Echo Meter Touch module requires a lightning data connection with a smartphone or tablet in order to work, and, unfortunately, many battery cases do not allow for external data connections. If you need some extra battery life while using your Echo Meter Touch module, you can use a battery case provided it has lightning or USB data pass-through.
Aside from increasing your phone or tablet's battery capacity, there are several ways to reduce the amount of power it uses:
- Before using the Echo Meter app, close all other apps that are running in the background. On iOS, double-press the home button and swipe each app panel upwards to close it. On Android, press the Recent Apps button and swipe each app panel away to close it.
- Lower the device's screen brightness.
- Once you start recording, press the sleep/wake button to turn off the device's screen while continuing to record.
- Rather than using the device's built-in GPS receiver, use an external GPS module paired via bluetooth.
For most datasets, it is very simple to transfer recordings to a computer over Wi-Fi.
- On your iOS or Android device, open the Settings app. Make sure you are connected to a Wi-Fi network, and ensure that your computer is connected to the same network.
- Open the Echo Meter app and navigate to the Recordings list.
- Tap the Edit button in the upper-right corner.
- Select the recordings you want to transfer by tapping on the dark circles to the left of each entry.
- Press the Share icon, represented as three connected dots, at the top of the screen. This brings up the Share Recordings prompt.
- Tap "WiFi" and wait while the app compresses your recordings into a single archive.
- On your computer, open a web browser and enter the URL exactly as it appears on the screen of your iOS device. This will take you to a web page where you can download your recordings.
This procedure will work with common household, single-router Wi-Fi networks. If you are on a school or corporate network and find that this method does not work, see instructions for using Android or iTunes file transfer below.
Android File Transfer
On Android devices, EMT recordings can be accessed from the device's internal storage under "EchoMeter > Recordings." Here, you'll find your recordings organized into separate session folders by date and time. These files can be copied to your computer using your computer's file browser.
iTunes File Transfer
For very large datasets, or when Wi-Fi is not available, the fastest way to get recordings off of your iOS device is to use iTunes on your computer. Please see the video below for a demonstration of this process, or this Apple Support article for a written guide.
The number of recordings are dependent on the available storage on your iOS or Android device device. The storage capacities on compatible devices span a huge range, so be sure to check the specifications of the model you have. Recording a few hundred typical, triggered recordings recordings per night at the 256 kHz sample rate will use around half a gigabyte per night.
If you are using the Echo Meter Touch 2 Pro, note that recordings made at a sample rate of 384 kHz take up 50% more space than those recorded at 256 kHz.
Yes, the app has been designed such that you can continue to hear and record bats while the screen is off. This is useful if you find the screen distracting or you want to prolong the battery life if you are running low. Just press the Sleep/Wake button on your iOS or Android device to turn the screen off.
We cover many species of North America, Europe, the UK, the Neotropics, and South Africa. The Echo Meter Touch uses the same classifiers as our Kaleidoscope Pro software. You can see the full list of species here. As we add regions to Kaleidoscope, we will also add them to Echo Meter Touch.
This is a very difficult question to answer. The factors that determine how far a sound travels include humidity, temperature, the source volume and directionality, and surrounding clutter. Additionally, no two microphones have exactly the same sensitivity, even brand new.
This white paper discusses all of the factors involved in much greater detail.