The LENA device has undergone all of the required testing for electronic devices, which you can read about here. 

Unlike a cell phone or Bluetooth device, the LENA device is a recording device only. It does not transmit radio or telecommunication signals. The LENA device complies with FCC radio interference standards for digital devices.

The LENA device does not have internet connectivity. Data transmission is accomplished via USB cable.

By virtue of having electronic components, the LENA device emits a small amount of electromagnetic interference, as do battery-operated toys, hearing aids, and the like. The LENA device complies with standards for electric toy safety.