No longer usable!

We have this baby monitor for approximately 6 months in use. Initially, the reception was very good. With a sound of the child struck quickly with us alarm. Another positive aspect is that you can adjust the sensitivity. Negatives: The buttons of the A and B channels are you proximity to one another, so we had it often goes unnoticed set incorrectly. When a sound signal is first comes a very unpleasant "cracking". Recently, "spins" this device completely. Either it does not register the noise of the weeping of our son (!!!!) or other noises or it cracks for some unknown reason. For us, this unit is now useless and ends up in the trash.