when recording sound for radio i usually switch my mobile phone to airplane mode. reason: the so called → cell phone interference considers my microphone cable as something to play with and disrupts the whole recording.
i recently participated in a → v2v (in german: car2x) testbed in south germany and recorded an interview in one of the cars. mercedes benz uses the mobile phone network to connect cars to cars and to their surroundings (as opposed to for example BMW and VW who use WiFi-p for the data transfer). due to the intense SIM card communication my audio was partly, well, destroyed. listen to the original:
of course, this is unuseable for broadcast. i loaded the material into → izotope RX 7. the wave/frequence spectrum looks beautiful to the amateur, but horrible to pros:
A) marks the undisturbed first seconds. at B) the first cell phone impulse sets in. you see the orange strokes all over the vertical frequency spectrum. all the patterns surrounding C) show how the interference takes over most of the audio material. D) visualizes a humble a part of the recording we would like to keep.
in previous years this would have been unrepairable. i applied the de-click module to the audio. de-click has a sub-module named GSM cell phone buzz. it cleaned up most of the mess. the processed audio has a few glitches, but i could use it for the broadcast: