Subtle hums have long been the scourge of anyone doing audio recording. For instance, fluorescent lights are a major emitter of low-level noise that fine (and even not so fine) microphones pick up, and computer monitors can be just as noisy as the fans and drives that they plug into. Turning off these electronics keeps them out of your recording. Now, whether you're a professional radio producer interviewing someone in an office or an independent podcaster toting a microphone with you for impromptu recordings of yourself or your friends, the ubiquity of constantly-connected phone devices may prove to be the bane of your existence as well.

The obvious thing is to turn off your phone before turning on your recorder, but that's not always possible, however. Say, for example, your waiting for an important phoen call. Also, for some people, their smartphone doubles as the audio recorder.

Here are some tips for getting better audio:

1.) Don't just turn off your smartphone, shut it down. (Not possible if your phone is your recorder as well, obviously). You want to ensure no network searches are launched, no Wi-Fi connects are sought and no phone calls are allowed in. Stand-by mode won't block it all out.

The second-best choice is to put the device on "Flight mode", which will cancel all network searches, but could still stymie your recording if you've got any alarms or alerts set.

2.) Ask your guest and anyone else in the room/area to do the same. Anyone's phone can emit a signal that your recording device will pick up. (And gently explain that putting the phone on vibrate is not the same as turning it off; rings are not the main problem—they're obvious.)

3.) Most important: always, always record with headphones on. The noise these interferences cause won't be audible to your naked ear during recording (just as the sounds aren't audible during our daily lives). But, as they are recorded, your headphones will relay them to your ears. The problem is that while not audible normally, once recorded they are not only audible on the recording, they are nearly impossible to eliminate from it.

The higher the quality of your microphone and recording gear, the greater the likelihood of this unwanted noise getting into your recordings. If you're spending money on gear, though, you can afford the time to eliminate as many possible snafus as possible.