How to remove air conditioning noise from videos
November 9th 2012
Echo Video have shot videos in some pretty difficult locations over the last 5 years. From hot air balloons controlled by a blind pilot to dangling off Telscombe Cliffs and almost drowning on a model boating lake in Hampshire, we’ve faced our fair share of trials. But one of the most troubling places to film is always the dreaded office block! Even if you get past the bland decor and inhospitable workers, you are often faced with the prospect of central air. This is when individual rooms don’t have separate air conditioning but it is all controlled from one central unit and there’s nothing worse when it comes to filming an interview. This is a problem we’ve encountered time and time again and it can really effect the audio quality, so here’s a few tips on how to remove air conditioning noise.
1) Ask to get it turned off – The simple ones are the best. You may really have to nag your client or the office manager and it won’t make you any friends but it will save you so much trouble when it comes to editing. It also means that if the client moans about the audio quality in the final video you can always use the classic ‘I told you so…’
2) Get the microphone as close as possible – Another simple sounding one that will make all the difference when it comes to editing. The closer the microphone to the subject means the recording levels won’t need to be as loud meaning you won’t pick up as much background noise.
3) Record a wild track – Before or after filming, record a few minutes of room ambiance. This will really help when cutting the audio together as it won’t leave you with “sound holes” when the background noise disappears completely. It can also be very handy for…
4) Noise reduction software – Products like Adobe Audition or free to download Audacity come with this handy tool built in. It allows you to capture a noise profile (ideally from a wild track) and then allows you to remove that sound from the audio. It’s not perfect but can make a big difference.
5) Manual noise reduction – The sound of an air conditioning unit is pretty universal and tends to be a low hum or “wooshing” noise. Using a graphic equaliser you can isolate the frequency that the noise is on and reduce the level. If you’re very unlucky the interviewees voice will be the same pitch as the air conditioning in which case you may have to resort to…
6) Add music or another sound – This simply acts to cover the noise you don’t want and should really be used as a last resort. It’s not ideal as the noise will still exist and may well still be audible underneath the music.
7) Don’t worry about it – Might seem a bit stupid this one but consider your audience. The majority of the videos we produce are being watched by people on their computers at work or home where there are constant noises that will cover any background noise on the video. Obviously if you’re producing stuff for cinema or headphone wearers this might not really be a solution.
At the end of the day central air is one of those unavoidable problems when dealing with corporate clients. The best thing to do is to persuade them to get out of the office and film in a venue where you can control sound levels, otherwise this is just going to be something that they are going to have to put up with. Just make sure you warn them first!