Echo/reverberation noises usually occur when you leave the microphone on while using Push to Talk. In this situation, the audio being played on the speaker tends to be captured by the microphone.
If you're close to your camera, try muting your phone or turning down the volume when using the Lollipop app to avoid loud echo noises.
Normally, this situation will not occur when you’re standing outside of the room watching a live view.
If the situation keeps happening, submit your request to our support team for further assistance.