Tuesday, October 1, 2019

Tips for Recording Sound when Shooting Video in Linguistic Fieldwork

I am a linguist doing linguistic fieldwork on highly endangered Khoisan languages. Part of my project is to produce video documentation of people speaking those languages.

As a beginning film maker, I have found the following tips to be useful in obtaining high quality sound recordings to accompany video. I have learned most of these the hard way, by actually making mistakes.

Turn cell phones off.

Believe it or not, many people have cell phones in rural Botswana, and on numerous occasions they have rung during a shoot. Tell people involved in your shoot, or close by to turn off the sound of their cell phones. You don't want your best video to be destroyed by the ringing of a cell phone.

Listen to the Ambient Sound

Before doing any shooting, take a moment to listen to the ambient sound. If you are inside, you should listen for things like the fridge, which makes a lot of sound, and also listen for computer humming and lights. Also, you can listen for echo (reverb) in the room. If you are outside, you can listen for things like music playing from shebeens (in Botswana). If you hear such sounds, it is sometimes easy to fix them. For example, to block refrigerator noise, it is sometimes as easy as shutting a door.

Make sure all mic batteries are working.

This tip holds for all equipment, but especially for mics since in some cases it may not be obvious that the battery is weak or dead. When you put away the mic, make sure to take out the battery (since if the mic is on, it will drain the battery). And always have a stash of fresh batteries available in the field.

Do not rely solely on the camera internal mic.

All video cameras (including DSLR) have a camera internal mic. As tempting as it is to flic on the camera, and let it record the sound, it is not a wise idea when doing linguistic fieldwork to record solely with the camera internal mic. The camera internal mic produces a noticeably lower quality sound than any high-quality mic (e.g., lavaliers or a Rode shotgun mic). If you decide to go with the camera internal mic (and no other mic) for convenience sake, you will regret the decision later on.

Whatever mic you use, try to reduce the distance from the mic to the speaker’s mouth.

The greater the distance the mic is from the speaker’s mouth, the more background noise that gets recorded, and the weaker the sound of the voice. Of course, you need to verify that the sound recorded is not distorted in some way by having it too close to the mouth.

Try to monitor sound using headphones whenever possible.

Even if the sound levels look OK on your recording device (e.g., Zoom H4n), there may be issues that you can only hear clearly when you monitor the sound using headphones. For example, you can more easily detect background noise (the fridge, wind, etc.), and take easy steps to reduce it (close a door, change the direction of the mic, turn off the fridge, tell the children to play a little further away, change locations, etc.).

Make sure sound is being recorded.

If you are not able to monitor sound using earphones, then monitor sound levels on your audio recording device. If you are not able to monitor sound levels for some reason, playback a test clip to make sure sound is being recorded. Always make 100% sure sound is actually being recorded. The worst possible outcome is to spend a lot of time setting up a shoot, and then realizing you do not have sound recorded (as has happened to me before).

There are different sound set-ups that may be appropriate for different occasions.

There is no perfect, one size fits all solution to recording sound. So make sure to think about your video needs, and to come prepared with several options. A basic choice you have to make is what type of mic you will use. Four options are: 

(a) camera mounted mics (for run-and-gun), 
(b) lavalier mics clipped to clothing, 
(c) a shotgun mic on a boom pole, 
(d) a mic visible in the video. 

On run-and-gun recording, see the following post:

Set the maximum recording level so that loudest sound is not distorted.

It is impossible to clean up a distorted sound post-production. If the speaker has a loud voice, reduce the recording level until the sound is far from being distorted. On the other hand, it is possible to increase the volume of the sound post-production. 

Play with recording levels (before shooting).

Play with recording levels to see what works best. In the run-and-gun set up, both the camera and the Rode have recording levels (there are only three for the Rode 0db, -10db, 20db). Play around with these and see what works best for you.

If possible and convenient, use two or more mics.

Using two mics will give you two sound files and that might be important when you do transcriptions (in case some word or phrase is obscured on one sound file, but not the other). Also, using two mics will save you if one of the mics malfunctions for some reason. Lastly, the mics might pick up different aspects of the scene (e.g., speaker’s voice vs. background sounds), and give different impressions. For example, lavalier mics yield a clear highly quality recording, but sound like they are close to the speaker. In some cases, you might want a more open sound.

Do not be afraid to shoot sound and video independently (dual system).

Some cameras allow you to record directly into the camera using an external mic, which produces acceptable sound quality. However, recording onto an audio recording device and onto the camera independently will allow you much greater options in setting up your scene (since the mic is not wedded to the camera). For recording independent sound, I recommend the ZoomH4n for the linguist. It has two XLR connections, and produces excellent quality sound.

If you shoot sound and video independently, remember to clap.

It is easy to join together audio and video using standard software. The purpose of the clap is to make sure that the video (hands coming together) and audio (a spike in the sound wave) coincide. The clap should be directly in front of the camera with the palms of the hands facing directly up and down, so that one can clearly see the two hands coming together. The clearer and crisper the clap, the easier it will be to align audio and video in ELAN later on.

Back-up your sound files with your video files, and give them similar names.

If you shoot audio and video independently, make sure you back up the sound files with the video files (in the same session folder, e.g., the folder for 2019_09_27). Also, give them similar names so that later on you can easily identify them.

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