It is common to find recordings mired by GSM cell phone interference—a “dit dit dit” or buzzing sound from the RF transmission that can creep into analog circuits. The De-Click module in iZotope’s RX audio noise reduction software has a preset built specifically for mitigating this problem.
Sample:
In this dialogue recording, we can hear the interference from the cell phone as a series of clicks:
Before RX:
After RX: