Film is an audio-visual medium, and yet many people focus almost exclusively on the visual side of things. When filmmakers fail to consider their sound, they often hurt their projects far more than they realize.

The fact of the matter is that most viewers won’t necessarily notice great sound work, but they will ALWAYS notice bad sound work. Even if it’s subconscious, nothing makes a project seem amateurish more quickly than shoddy sound .

So while sound design is probably not why you became interested in film, it still remains a vital component during all stages of filmmaking: pre-production, production, and post-production.

Production Audio#

Setting Your Levels#

When you set your audio recorder to the proper levels, you’re adjusting how quietly or loudly you will record sound. The goal should always be to record audio loud enough that the quietest sounds in the scene registers on the device, but quiet enough so that the loudest sounds don’t get clipped. Clipping occurs when sound is recorded so loudly that the audio is distorted. This can be referred to as the audio peaking.

Luckily, you don’t have to set your recording levels just by ear. You’ll likely be looking at an audio meter that will show a range of numbers from a very low negative number all the way up to 0 or 6 dB. In general, you want to adjust your sound settings so most of the dialogue in your scene is falling somewhere between -20 and -10 dB (probably closer to 10 if possible). There’s no exact right number here since everyone hears things differently and has different preferences for how loud something has to be. However, there is an exact number when it comes to peaking and that number is zero. To avoid audio distortion, make sure all your audio stays below 0dB.

Then, while audio is being recorded, you’ll be able to monitor the lights moving up and down on the meter. Green lights mean you’re safe; yellow lights mean you’re approaching a level where the sound might peak; and red lights mean you’re peaking. You want to ensure that the quietest sounds register as green while the loudest sounds don’t quite hit read. If you’re doing a rehearsal, this is a great time to play around with your meter to find the perfect level. Otherwise, it’s not uncommon for the sound recorder to chat with the actors before a scene just to get a sense of how loud their speaking voice will be.

Adjusting Your Levels#

IN SCREENPLAY FORMAT:

WIFE

(whispers)

You forgot to run the dishwasher again.

HUSBAND

(bellowing)

NO IT WAS YOU WHO FORGOT TO BUY MORE DISH SOAP!

Now undoubtedly this is a compelling scene full of rich drama. But unfortunately it will be a very difficult scene to record. So what is an intrepid young audio recorder to do when the quietest and loudest moments in a scene are so far apart from one another?

Well, for starters, don’t adjust your levels mid-scene. It may seem logical to begin this scene recording for the wife’s volume and then crank the levels way down when the husband starts screaming, but it’s important to remember that adjusting the levels effects all audio. If you adjust your levels throughout a scene, the room tone (the natural “background” noise) will change wildly over the course of the scene.

Do move your microphone. If the microphone is further away from a sound source, then it will record that sound more quietly. Therefore, in the scene above, the boom operator should try to get the microphone as close to the wife as the framing will allow, but attempt to keep it far away from the husband when recording his lines. They just need to be careful as they move the microphone to still keep it pointed in the right direction. Moving a microphone away from a subject will make the recording quieter, but pointing a microphone to the left or the right of the subject will make the recording muffled.

Do set different microphones to different levels. If each actor is outfitted with a lav, you can adjust the lavs to record at that actor’s speaking voice. Lavs are only meant to pick up dialogue anyway so you’ll be relying on a boom or a camera’s internal mic for room tone and background noise. Therefore, you can make the wife’s mic very sensitive and the husband’s mic very insensitive and get crisp audio of both of their lines.

Five Things to Keep in Mind on Set#

1. Turn Things Off - Before you start shooting, turn off anything that’s going to make a sound that may in any way muddle you audio recording. This might include the air conditioning, radiator, or even the refrigerator. (Tip: Put your phone inside the turned-off refrigerator. That way you won’t leave set without remembering to turn it back on).

2. Slating - Explained more extensively in our post about on-set direction (LINK TO BE ADDED), slating plays a crucial role when it comes to sound. When that clapboard is “clapped,” it provides a sync point if you’re trying to sync your audio to your image by hand. It’s important that the clapboard is clapped cleanly, with the person holding the slate pushing it down forcefully into its final position. If for any reason, the clap isn’t perfect — someone is talking over it or the slate holder lets it fall so it clatters— it’s important that you slate again. This is called “second sticks.”

3. Listen As You Go - While it’s important to keep an eye on your levels, it’s also crucial that you actually listen to the sound being recorded with headphones. Just like the human eye adjusts for bad lighting, the human ear is remarkably good at adjusting for bad audio. The whine of machinery or the sound of a helicopter overhead can be tuned out easily enough if you’re not paying close attention while listening on headphones.

4. Speak Up - While speaking up may be met with grumbles and rolled eyes from the rest of the crew, it is vital that the sound recorder say something if there are any issues with the audio. If there was a disturbance during the take or the audio peaked, make sure to say “We need to go again.”

   Likewise, if the director is about to call action and you hear a plane overhead, you should call out, “Hold for sound!” and let everyone know when the plane is out of the microphone’s “earshot.” That way, everyone doesn’t waste their energy on a take that you knew from the start would be unusable.

   (A corollary note for directors: Check in with your sound person before saying that you’re ready to move on. This makes it far less awkward for them to speak up and say that they need to go again.)

5. Room Tone - Before moving on from any location, make sure to record a minute of total silence in the same conditions you were shooting in. (Don’t turn the fridge back on and then record room tone). It’s crucial that everyone stop their work for a full minute so that the sound recorder can capture enough room tone to use as “fill” in post-production.