What is Hiss?

Not to be confused with hum, hiss is a persistant noise on a recording that sounds like … well … hiss. Turn the sound up loud enough and you will almost always here some on your recording. A low levels, it isn’t much of a problem.

The problem is when you have hiss on a recording that is distracting – say from a bad microphone or from turning up low dialogue. You could also be trying to restore an old recording that has hiss on it. Wherever it comes from, however, it’s annoying and needs to be destroyed.

The Basic Method of Getting Rid of Hiss

Hiss removal involves a few similar steps no matter what software you are using. First of all, you need to find a sample of hiss just by itself. That way the audio program knows what the hiss actually sounds like isolated – before that, it could get hiss confused with other parts of your recording. After setting some parameters, your tool of choice will try to remove that hiss from the recording without damaging any other areas.

To illustrate, I am going to take a look at removing hiss from two programs: Audacity and iZotope RX.

Removing Hiss with Audacity

If you are not familiar, Audacity is a great (and free) audio tool for Mac and PC. You can get it here. To get started, open it up, and import a piece of audio.

After importing your track, look closely for a small chunk of audio where there is only noise. After you’ve found it, select that portion of audio.

Select Noise Removal… out of the drop down list of effects from the Effects menu. This will give you a little dialog box that presents a handy two step guide. The first, is to get a noise profile. Since we’ve selected our noise profile area, we can just click the “Get Noise Profile” button.

Once you have the noise profile, deselect the noise profile area, and get back to the two step panel. You can adjust the noise reduction amount, preview it, and hit okay. Play back your audio, and the hiss is now minimized or gone.

As we mention in our limitations section, your audio may be affected depending on the Noise Reduction level you’ve chosen. If you are getting audio that sounds like it was recorded underwater, it is time to go back and rethink your parameters.

Removing Hiss with iZotope RX

iZotope RX is a fantastic program that is well worth the fact that it is not free. You can get it at BHPhoto.com.

What does iZotope RX have that free solutions don’t have? Well first of all, it can do a lot more than take out hiss, but we are sticking to hiss in this article. One of my favorite features of iZotope RX is its Spectrogram information. It can be viewed right on top of the more conventional wave pattern:

This view allows you to see – in much greater detail – disturbances or irregularity in audio. For instance, hum can be observed as a single line shooting horizontally through a recording. Hiss appears as “noise” you can see in the background of the audio.

Removal works in a similar fashion to Audacity. Find a portion of the audio where just the hiss is present, click the Denoiser button and click Train. This will “train” the program in the audio noise profile of the recording.

As in Audacity, you have a Noise Reduction level and a Smoothing option. However, you also have a choice of several algorithms that might give different results. Some take longer to process, but it is worth it to see which one might fit your situation the best.

When using an advanced program like iZotope RX, it is a good idea to look through their documentation. In the case of iZotope RX, the documentation happens to be extremely helpful and thorough.

Limitations

Of course, there are limitations. Like we mentioned in our previous post, audio is like a bowl of soup. You are going to take out some things you want to leave in. Since every piece of audio is very different, you’ll need to do some experimenting with parameters to see what level of removal leaves your audio suitably in tact.

Now.

Direct Actors for Improv

Home Film School Student has a conversation with an actress about being directed in a scene where she ab-libbed quite a bit (and they wanted her too). The content of this video is valuable if you encourage actors to improv during a scene (this may be more helpful for them, actually), but my favorite parts of this video are meta. Such as the dude asking “are we ready to go” at the beginning, and this “bored camera guy” shot.

I’m trippin! Check out the videos here.

The Beeping! The Beeping!

For the first little while I worked with Final Cut Pro I had no clue why some audio would beep on the timeline and need to be rendered while others did not. Turns out it could be a few reasons, and Genius DV has laid them out in a handy little post.

For your health.

IndyMogul Really Wants You To Make a Slider

Zach from Backyard Effects and IndyMogul will stop at nothing to get you to make his $20 slider. Nothing.

Nothing.

Partner with YouTube Instructions from a YouTube Video

Did I just blow your mind? Maybe this video will. From FilmmakerIQ.

DiY is basically going to apply. Basically.

Young Man Reading a Newspaper While Yawning Tracking Shots with Smooth Jazz

It’s a common and difficult problem, so we are going to do a series of articles on how to deal with different types of audio problems and with what programs. But before we get fancy, we have do get down to some basics.

Enhance!

I like to sit down and enjoy an episode of a procedural crime drama like “CSI: Miami” or “CSI: Someplace” every once in a while, but I have to laugh when they deal with anything audio or visual. The common use of technology that doesn’t exist is the “enhance!” feature where a blurry security camera is somehow enhanced to allow us to read a license plate off the back of a car. It’s fun, but it’s stupid, because you can’t do that in real life. It’s just technically impossible to create data where there is none.

The same goes for their treatment of audio. Usually, a garbled piece of audio is brought into their A/V department and it comes out pristine, so they can get the one piece of evidence they need. Usually this can be done with Horatio standing over the technician’s shoulder.

Like the video part, the audio treatment is completely fabricated, but it plays into a common misconception about audio in general: that you can “remove” something from it or “enhance” a part of it easily.

Can you do those things? Yes, but it is much more difficult than TV has led everyone to believe.

Audio Soup

Think of your audio track like a big pot of soup. There are spices, carrots, peas, chicken, and a bunch of other stuff all mixed together. It’s delicious, but has a flavor problem. It would be much better if we took the carrots out. Okay, no big deal. You can see the carrots – they’re orange. You get a spoon and start picking them out.

So you start taking the carrots out, and you soon find out it’s not as easy as you thought. You keep removing parts of the soup you didn’t intend to, like some broth. But after a while, you manage to get them all out. You took some of the soup with it, but that’s going to be okay.

Now, for your next assignment, you have to take the oregano out.

What is “Fixable”?

Audio is like the soup – all mixed together and messy. You can’t just “remove” something easily and without consequences, but if you know exactly what you need to get, you can take it out with some work if you don’t mind losing a little bit of other audio in the process.

What makes something a carrot? It has to be something that is uniform throughout the audio, like a hum or a hiss. Something that can be easily identified and is always there. The carrots are still in the soup, they are just identifiable.

Obviously, it’s impossible to remove the oregano because it’s too much a part of the soup. If you really wanted to take it out, you’d damage the soup heavily, and you’d have a hard time figuring out what is oregano and what isn’t. There would probably be some left in there when you’re done too.

The oregano elements in audio are things like a cough or a car in the distance during dialogue. It’s too embedded in the sound to be completely removed.

Next: Removing the Carrots

Soon, we’ll be posting round 2 of talkin’ about audio, with a list of tools to remove carrot-like audio problems, and some methods. Stay tuned!

Operating a boom mic on a set is an interesting job. In Hollywood, there are people who just operate boom mics. It’s their job. They literally spend all day boomin’ it up, and they’re good. Real good.

On the independent/DiY level, you are very lucky if you come across someone who is proficient in boom pole operation. You should probably give them an edible arrangement and be best friends with them if you find one. Never let them go. Never.

For the most part, though, you will be going through a familiar scene: trying to train someone to use a boom pole quickly so they do a decent job. Could be for one scene or a whole day. Could be because you forgot, our the edible arrangements made your first boom pole guy sick. It doesn’t matter. You need audio, and your brother’s girlfriend isn’t doing anything for the next 30 minutes.

So, we’ve rounded up a few tips to make sure you communicate, and you’ll have some decent audio flying your way.

Photo Credit

Pointer #1: Point the tip of the boom mic at the sound source

This one is important, because it’s not instantly intuitive. It’s always good to explain to your boom operator that the slits on the side of the boom cancel out noise, and the real audio capturing takes place at the tip of the mic.

This immediately removes some common problems of boom operators pointing mics at shoes and tea pots when they should be pointing the mic at the mouth of the person talking. The concept is simple – point the boom at the sound source like an arrow.

Pointer #2: Ask for / watch the frame line

Nothing stops a shot dead in its tracks faster than a wandering boom mic, unless you are in this scene:

Make sure you communicate to your operator that before every shot, they need make sure they know (roughly) where the frame line is, so they don’t cross it. One of the best ways is to show them the shot, so they know where their boundaries are.

Easy – no more wandering booms, and no more tears. This is especially important, because it’s embarrassing for a first time operator to single handedly ruin a take.

Pointer #3: Keep Steady and Stretch Between Takes

A boom pole / mic combination might not seem that heavy at first, but holding it at length can take its toll on anyone. Communicating to your operator that they need to keep steady during shots – but not between shots – will encourage them to limber up keep their endurance up for the duration of the shoot.

Photo Credit

Pointer #4: Try other options besides over top

The classic boom operator position is the boom high above the head, but sometimes a scene is much better served from a different position. Communicate to your boom operator that whatever position gets the mic the closest to the source and outside of the frame line is the best option, and up above is not the only way to do it.

Pointer #5: Some movement is okay, but keep it consistent

Inexperienced boom operators have the tendency to hold a mic absolutely still in the same position for an entire scene, even with moving action. Communicate to your boom operator that if there is movement, they should follow the sound source. However, let them know that for consistency, boom movements should happen with the sound, and not while it’s stationary.

—

That’s it! Just 5 quick points, and you’ll have a solid boom operator on your hands! We’ll have more in this series coming down the road, so stay tuned!

Panel is:

Adam (@adamfairholm)

Doug (@thedougmovement)

Lance (@omegabane)

Picks

Lance K-Tek KE-89CC boom pool

Doug Fun with Rap Music

Adam M-Audio iZotope RX Complete Audio Restoration Software

File: http://www.diy-filmmaking.com/podcast_files/ep7_box_it.m4a

Now let’s take a look at another situation. You’re out shooting in the snow, and you have a protective cover around your camera. You are just looking to get the shot – you don’t have a microphone connected and you are just using the internal mic. Afterwards, you get into your editing software and look at the footage. The video looks great, but the audio is – as expected – lacking. Since you had that protective cover on and were just using the internal microphone, you got sub-par audio.

The thing to remember is audio is a very important part of the experience the viewer has when watching your film or documentary. You can show footage of a carnival, but what is a carnival without the sounds that come with it? I’m talking about the screams, laughter, noises the rides make – all of it.

In this situation, you would have learned something important about ambient noise. For the user to full embrace the experience of being out there on that snowy hillside, they need to hear the soft breeze and the even softer sound of the snow falling. They need to hear a high quality recording of that, as well. This is what is known as ambient noise, and it can make a world of difference.

There are two routes you can do with ambient noise in terms of procuring it. If you think of it, of course, you can make your own, but sometimes a smarter idea is to get some ambient noise from another source.

Recording Your Own Ambient Noise

One obvious path is to record some ambient noise of your own when you are on location. This is sort of the same idea as room tone – you need to remember to actually record it, and record it without any blemishes or unusable qualities. For example, having your actors talking in the background about how the shoot went will probably take away from your carnival atmosphere.

Yes, there are some pluses to this method. Your ambient noise will be unique, and it will be recorded with the same equipment as the rest of the audio. However, I think that in many cases, recording your own ambient noise may be the wrong desicion.

Using Canned Ambient Noise

The term “canned” isn’t a very good one to use here. If you find good canned ambient noise, it’s very effective.

Take the example of the carnival. The ambient noise of the carnival may be a little sad when you choose to record it. There may not be laughing people in the background, or tilt a whirl sounds. In short, it may suck.

However, when you find a recorded piece of carnival ambience, if its good, then the person who is recording has taken the care to get great carnival ambience sounds. Maybe they even recorded some sounds separately and put them together to get something that’s really great.

The point is, using canned ambience could be a really effective way to give an extra boost to your image. It could make your carnival scene more exciting, or your outdoor shots have more impact. It can really boost up your production values with little or no cost to you.

What’s a good place to get ambient noise? Be careful – there are a lot of leftover sites from the 90′s with crappy siren and explosion wavs that will obviously make your film look stupid. Try a site like The Freesound Project – they have great, high quality sounds that are unique and fit a wide variety of situations.

Ambient Noise and Dialogue Scenes

Although ambient noise can play an important role in just shots of environments, it can play a very important role in dialogue scenes where there needs to be ambient noise.

Take the classic example of the restaurant scene. You are filming two actors talking to each other, with a restaurant chatting away in the background.

When you cut this scene, you don’t want a great cut to be ruined by background chatter that doesn’t cut together gracefully. Instead, you just tell your extras to look like they are talking while keeping quiet, and add the general chatter in post, allowing you to edit dialogue worry free.

————

Although ambient noise is something a lot of filmmakers may overlook in the post process, planning for it and getting it are two efforts that will yield some added production values to your films.

What happened? Well, inside of that gap is complete silence. Absolute digital silence. But wherever you are reading this right now, close your eyes and listen to the room your in. No room is absolute silence, and the quiet subtleties you are hearing in your room are known as room tone. It’s important to know how to use room tone to avoid audio editing difficulties.

Ideally, for shooting dialogue and other similar scenes, your shooting room should be very quiet – free of air conditioners and helicopters outside. But even the quietest room has a different sound to it, a different tone. This could be affected by a lot of things. For example, what is on the walls? Bare walls along with no furniture and tile floors bounces sound around and you get a more echo-y, hollow sound. A lot of soft furniture with things on the walls (especially something like a hanging wall carpet) absorbs sound, and you get a warmer sound.

The point is, each room is different, and a smart thing to do for your production is to recognize this and use it to your advantage.

Getting Room Tone

The easiest way to get room tone is to make a habit of adding in one more step before wrapping a room during shooting. Before everyone packs up for the next setup, tell everyone to “hold for 30 seconds of room tone”.

Everyone should get quiet, and whoever is recording audio (it could be you), should identify the room tone take into the microphone, and point it horizontally for 30 seconds. If someone coughs or falls down, start again.

When you get back to your editing program, and you have a folder with your scene files, you should now have one you’ve named “Room Tone”. You may use it, you may not, but it’s the mark of a good production to always have it handy for each location.

Room Tone vs Ambient Noise

Remember that room tone is different than ambient noise. If you are shooting at an amusement park and want the sounds of the crowd having fun, that’s ambient noise. It’s too busy and varied to be room tone. We’ll talk a little bit more about ambient noise later this week.