If you are like many of todays video hobbyists, you may have spent thousands of dollars on your video gear. Go on. Add it up. You invested $2000 for that fancy digital camcorder, several hundred for professional lighting gear, a couple hundred more for some good mikes and audio cables, not to mention a few grand for that nifty nonlinear editing system. What you may not realize is that all of that technology can be wasted if you fail to use a simple set of $10 headphones.
All too often audio is a forgotten element in making video. As a result, getting good sound on location is rapidly becoming a lost art. In fact, because most consumer camcorders dont have manual audio controls or VU meters, it can be difficult to know if you are recording any sound at all, much less good sound. Audio disasters can be very common, but most are avoidable if you follow this one simple rule: use headphones when you shoot.
Imagine coming back from the family reunion, where you conducted a once-in-a-lifetime interview of your grandfather talking about the old days, only to find out that the sound of the kids playing across the hall had drowned out every word grandpa said. Or to start editing your cooking demonstration video, only to find that the hum of an air conditioner ruined your sound track. If the batteries in your wireless mike went out in the middle of recording the wedding vows, would you know? You would if you were monitoring your audio with headphones. Had you worn a pair of headphones when you interviewed grandpa, you could have hushed the kids or moved to a quieter place. If you had worn headphones during the taping of the cooking show, you could have noticed the hum of the air conditioner and switched it off before rolling tape. And only a pair of headphones would have cued you to switch batteries before shooting four hours of silent wedding video.
The best way to make sure the audio youre recording is usable is to listen to it while youre recording. But just standing next to your camera isnt enough. Your ears dont hear things the way your camcorder does. You must listen to exactly what the camera is recording, and thats what the headphone jack is best used for. Plug your headphones in and listen up.
Your mother was right when she told you there was a difference between hearing and listening. Simply putting on the headphones and hearing a signal isnt audio monitoring. What does the quality of the audio sound like? Are there any unusual noises or hums? Try to pinpoint the source of every single sound you hear on your headphones.
Your brain is a powerful tool. But sometimes it can trick you. We all have selective hearing. In the middle of a conversation, for example, your mind tunes out certain sounds and noises in order to focus on the discussion. Over the course of our lifetime, weve learned to tune out the background noise. Your camcorders microphone doesnt do this. It records every sound it hears, without prejudice.
Putting on headphones and listening enables you to hear the heater when it turns on, or the buzz of the computer screen. If youre using the internal camera mike, you may find that it picks up the sound of the zoom motor on the camera when you change your shot, or even your fingers pressing the camcorders menu buttons. Sounds like these are the audible equivalent of invisible to your ears. But not to your camcorders mike. Headphones can help you hear things that your ears alone might never hear.
Take charge of the sounds you can control, and minimize the ones you cant control. If youre talent isnt speaking loud enough, try moving the mike closer. If you hear a hum from a refrigerator, unplug it for a few minutes. Turn off any TVs or radios that are on. Close windows and doors to help eliminate traffic noise. Once you have identified audible hazards, you have the opportunity to prevent them from being recorded to tape.
When monitoring audio, listen to whats not being said before you listen to anything else. Before you start to record anything, put your headphones on and listen to the silence. More than likely, its not silent at all. Most places have some sort of ambient noise. Decide if the ambient noise is overpowering the audio you intend to record. Often if helps to close your eyes when youre listening. By not using your eyes, you are forcing yourself to rely on your ears for information. Youll be surprised at how well this simple trick can help you concentrate on what sounds you are recording.
When you start recording, continue to monitor the audio. Audio levels can change over the course of time and background noises can suddenly appear and disappear. Your subject may become excited and start talking louder, or a breeze may blow on the mike, adding wind noise to your soundtrack.
Some cameras have automatic gain control (AGC). This technology monitors the level of the audio signal being recorded and automatically adjusts the input level up or down. Sounds great, right? Wrong. Your camera cant differentiate between the sounds you want to record and the noise you want to avoid. Imagine recording a scene in a crowded restaurant to add a little ambiance to your video. The clinking of glasses and various other restaurant noises will add depth – if the sound of your speakers voice is clearly heard above it. However, when your talent takes a breath or a dramatic pause, the camera automatically boosts the record level in an attempt to record a strong signal. The result is amplified noise. When your speaker says his next word, the AGC will realize the signal is too strong, and rapidly drop the audio level. You end up with a soundtrack that goes up and down more than a roller coaster (see Figure 1). If your camcorder lets you, switch off the AGC in favor of manual audio control. Unfortunately, most consumer camcorders dont give you this option, and youll have to work around your AGC. The point? You cant fix what you cant hear.
The Right Fit
The headphones you use will make a difference in how well you are able to monitor your audio. Closed ear headphones cover your entire ear and work well to block out surrounding noise. But they can also be bulky, and can make it difficult to interact with people. Be careful when using them outside near traffic, too. Not being able to hear the sounds of oncoming cars can be dangerous.
Open ear headphones tend to be more lightweight and portable, but because they dont cover the entire ear, they can be difficult to use in noisy situations. One solution is to cup your hands over the headphones when getting critical sound and level checks.
When shopping for headphones, versatility is key. Whatever headphones you prefer to use, make sure they are comfortable. Lets face it, if youre uncomfortable wearing your headphones, you wont use them.
Avoid the traps
When you use your headphones, make sure youre using them correctly. Plug directly into the jack on the camera. Plugging into a wireless receiver that is upstream of the camera is a common mistake. You may hear great audio in your headphones, but youre not listening to what the camera is recording. If theres a problem with the connection between the camera and the receiver, you wont know about it until its too late.
Dont forget to make sure your headphones are working. You may have great audio going into the camera, but panic when you dont hear it in your headphones. Some cameras have a volume control for headphones. Turn it up.
Many consumer cameras simply dont have a headphone jack. If you can, get a camera that does. If you cant, dont let that be an excuse. You should still monitor your audio. If you have RCA outputs, plug your camera into a monitor that has a headphone jack and use that to monitor your audio (see Figure 2). At the very least, record a short segment and play it back, just to be sure.
Customize your gear. If you need to use a closed set of headphones but still want to hear existing sounds, take one side of the headphones off. Some high-end headphones allow you to put different covers on the earpieces. Try combining an open ear set with full ear set. It may look funny wearing them, but the goal is to get good audio to go with your video. Fashion is secondary.
Using your headphones should be a matter of quality assurance. By making sure you have the best audio possible when youre in the field, youre giving yourself a head start on the editing process. The fewer problems you have with your audio, the more time you can spend putting the finishing touches on your video.
So dont let audio problems poison your video. On your next project, use headphones to monitor your recording. This way, you wont have any unexpected audio gremlins sneak into your video. When it comes to getting good, clean audio, an ounce of prevention is truly worth of a pound of cure.