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Avoiding Mouth Noise / Mouth clicks

Andrew Troedson
Lately I've had to do quite a few voice-over recordings with non-professional voice people (ie lecturers; students; even a fireman!). I've noticed that I'm getting a lot of mouth noise (little clicks etc.). What are some ways to avoid this? Is it just a matter of mic selection? Mic placement? Are there any particular pop filters (or click filters) that would help?

Also, if a recording does have some of these unwanted noises, what is the best way to remove them? I've been manually zooming in and cutting out the unwanted bits in ProTools, and, while this is effective, its mind-numbingly tedious. (Its also not a very helpful method when sync is required.) I've tried redrawing the waveform with the pencil tool, and that's even more tedious!

Michael Rempel:
The best pop filter is distance from mic. I dont know what 'pros' do but I do voice-overs on occasion, and I drink unsweetened cold tea to keep the palate clean and avoid noise. Gator aid works too.

Part of my technique is that I always do the material standing up. I practice listening to my breathing through my mouth for a while before starting, I make sure my mouth is damp but clean, and I will clear my throat with some terrible sounding singing if need be.

I use a hand held cardioid, taking it on and off axis as the sound demands. I try to work the mic at least 6 inches away, and up to 15 inches, using mic technique to supply natural compression. I take the mic away for breaths.

The law of signal to noise ratios apply to voice overs too. Make sure the recording is a strong clear but not overly excited voice (unless you want excitement) Pretending that your listener on the other end of the mic is an intelegent but slightly deaf person can be quite helpful. Using the power of ones voice adds clarity and makes for better articulation. The clicks you complain of are burried in the noise floor.

As to what processors to use for clicks and so on, try gates and filters. loop a few prevalant sounds and see if you can filter them down with a narrow notch parametric, set the Q around 10 or so, -12 db and hunt for the frequency or frequencies then set up filters accordingly.

If the noise levels are quiet enough, and not in the voice you might get some of them with a gate.

I dont know if there are any good books on the subject, but I would also be interested in learning more about good voiceovers. Most of this I have just picked up on my own out of a desire to get good sound.

Mind numbing tedium is often the only answer. I did 3 hours of old bad recordings that way a while back.

Charles Deenen:
One way to help this is by not positioning the mic on the same axis as the mouth. Hang your shotgun type mic about 2-3 feet above the person, about 1-2 feet in front of them, pointing towards their stomach (or belly :). This will also give you a much more realistic sounding "production dialog" sound. If you're going for the film-trailer-like VO (i.e. big voice, close-up recorded), mouth clicks can really only be cut out by hand. During the last few years, our editors used Sound-designer's smoothing function to remove them.

During the recording however, try to find out if there are ways to make your voice-talent click less. i.e. drink water etc. Often, there are ways to limit their clicky-ness (except when their teeth and dentures are rattling in their mouth. Superglue it... :)

Brad Fuller:
Make sure the talent has plenty of water and don't put the mic too close (the inverse square law is important here.) You can also direct them to yawn and to notice how their mouth opens inside. Often, more noise comes from speakers keeping their mouths too closed when they speak. You'll have to watch this because you don't want amateurs to be more worried about their mouths than their lines.

Pop filters do not help mouth noise. You'll always record some mouth noise, it's unavoidable. Also be aware of the final product the speech will be in, it may be masked anyway.

Randy Thom:
I disagree a little bit with some of the other responses in that I think mic placement is not likely to help you much with the problem you describe. The sounds you don't want are coming from the same place as the sounds you do want. There is no way you can point the mic in such a way as to reduce the clicks without also adversely affecting the sound of the voice. The "inverse square law" affects the voice in exactly the same way it effects the clicks.....if you move the mic farther away the clicks will be quieter, but the rest of the voice will be equally quieter. When you turn the voice up later in the mix the clicks will be turned up exactly the same amount becauswe you haven't changed the ratio between the voice and the clicks by moving the mic farther away.

This is a problem film dialog editors encounter constantly. I would recommend that you try using volume graphs in ProTools to reduce the level of the click moments (works great for sibilance too) as an alternative to simply cutting them out. This approach won't change the sync of the dialog, and if you're careful it can sound very natural. True, it's a lot of work. But look at it this way: if there was some magic way of getting rid of clicks, and other similar problems, everybody who lives on your block could be in the same business you are in.......and that wouldn't be very good for business, would it?

Brad Fuller:
not so about inverse sq law: mouth clicks are most often the same gain. But, a voice can project much louder. Just a few inches can be very important (depending on how close the speaker is to the mic)

I strongly suggest that you fix the problem before the recording, not after.

Roland Morris:
A large part of the problem is the unnatural dynamics you have with a close mic and the un-ear like digital recorder. In the days of analog, these sorts of extremely fast rise time/high energy transients simply wouldn't make it past the playback head. The sound would be slewed and limited to a natural level.

One solution is to simulate analog with a freq dependant limiter with an extremely fast attack and release time set to trigger above the sibilance frequencies (shelf filter 10k upwards) but this is difficult to set if you have new talent every two hours.

The best solution of all is a room humidifier and a glass of warm water to sip on.

joel newport
Actually there is something close to a magic way and thatıs the Sonic Solutions de clicker. It is both manual and an "automatic" version but I find the manual to be much better. You have several algorithms to choose from and simply high-light the click and select the algorithm and in about 2 seconds its gone. I do film dialog and commercial dialog with it all the time and its amazing and quick. It allows me to let the talent get close to the mic for that warm sound without worrying at all about the clicks.

Ray Gillon
A glass of water is a simple reply. I work a lot in foreign language dubbing of movies and in North Europe the air is drier due to the cold, and we use humidifiers, or simply beakers of water on the radiators. You could hose them down, but I am not sure it would be totally appreciated.


I disagree a little bit with some of the other responses in that I think mic placement is not likely to help you much with the problem you describe

Henry Howard:
Not So.

Many, though not all, mouth noises originate well within the mouth cavity. Positioning the microphone so that it is not aimed at the tonsils can and will reduce some mouth noises. Saliva pops usually occur at the rear of the mouth and back teeth. Again, avoiding that area of pick up can greatly reduce the problem. Stopping as required to moisten the mouth may be necessary. Avoid drinking coffee and other beverages that tend to create dry mouth. Also avoid carbonated beverages as you will then be hearing the bubbles from the talents stomach.

Recent surveys show that ninety percent of adults have, on average, 23.5 teeth. And fifty percent age 55 and older wear partial or complete dentures. So glue might also help. Now, in the right hands, glue will create a temporary repair but 95% of the time, the denture wearer does not have the skill or understand the technical requirements to do it correctly.

Randy Thom
Hmmm....last time I looked, the voice itself mostly also "originates well within the mouth cavity." Pointing a mic at the side of the mouth will reduce spit and smack noises a little bit, and it will also give you a different, and probably to most ears, inferior, recording of the voice. If it didn't then you'd see more mics pointed at the side of singers' mouths. Vocal mics are almost always pointed directly AT a vocalist's mouth because the voice sounds better there.

Michael Rempel:
I believe the suggestion was above the vocalist, not beside. A voice travels in a straight line up the throat, and is subject to a sudden bend at the end (mouth), but sound likes to travel in a straight line. The natural consequence is that above is the best off line position for a mic.

I have been told that choir and other music teachers have know this for centuries. They teach voice projection through the upper palate for the strongest voice.

Roland Morris
A lot of voice character comes from chest and skull resonance. In my experience, everybody needs different mic positions to get the best out of their voices. Sometimes a big growly voice needs to be close miced and a quiet thin voice needs a few feet to develop. The opposite of what you'd think.

Talking about voice recording here, not ADR or singing. I start with a cardoid or hyper-cardoid mic slightly off axis (pick a mouth corner) at cheekbone height aiming slightly down towards the chest and adjust distance for dynamics. This gives minimal sibilance and popping which can permanently destroy a recording. If the room acoustics suit the voice required for the particular job, then I'll back the mic off a bit more and maybe use figure of eight or omni.

Mouth clicks will be less and less important with mic distance and I wouldn't compromise mic positioning because of them. If I can still hear them in the mix with everything else, then I'll deal with it with a quick paste of room fill. (thats room ambience). In all the thousands upon thousands of dialogue edits I've done, I've rarely encountered clicks in the middle of a syllable but it does sometimes happen. Lip smacks and tongue/palate clicks generally happen in the clear.

When editing drama dialog, you have to consider was the click intentional or suited to the script and is best left in at a reduced level. The same goes for breaths which I very rarely remove but generally reduce to taste, especially first breaths if there's a compressor in the chain.

Randy Thom:
I'm certainly not trying to steer people toward expensive solutions, or necessarily toward trying to fix everything in post. The original question on this subject was by a guy who said that he has access to ProTools. People at Skywalker where I work do wonders every day removing voice smack/click sounds with ProTools, so it's an approach I'm very familiar with.

The way you approach any job in sound recording is dependent of course on your role in the project, the budget and time available, the end-product format, tech specs, venue, etc. There is no one-size-fits-all solution to anything.

I would say this, though.......mouth smack/click sounds are not necessarily a problem which the recordist should try to address at all. There are some problems, like "p popping," which can ruin a recording and do have to be addressed and solved while the original recording is being made. On the other hand, mouth clicks, annoying as they can be in the original recording, CAN be fixed in post...assuming there IS a post and it's not a live broadcast or a project with no budget for post. My point is that I wouldn't want the person pointing the mic to do anything too drastic in terms of positioning in an attempt to reduce the clicks, meanwhile degrading the sound of the voice in the process.

It's easy for people like us to get obsessed with a problem like noise, sibilance, clicks, etc. to the degree that it blinds us to every other consideration. Many dialog re-recording mixers in movies have processed the life out of actors' voices in an attempt to get rid of noise. I've done it myself a couple of times in the distant past.

Another theme this issue reminds me of is what I call the "just tell me the secret" phenomenon. Many of the posts on forums like this one are from novices who think, or hope, that for every one of the problems they encounter in recording, fabricating, and processing sound there is a SECRET trick solution, known only by the clan of audio gurus. What is the magic mic position which gets rid of clicks? What is the secret to getting rid of distortion and ambient noise? What is the plug-in which will turn my dog's growl into a T-REX scream? The answer is almost always that there is NO simple way to do any of these things. The answer is inevitably lots of hard work and lots of experimentation.

So, my answer to the original posted question was basically...I know it's hard work to manually deal with each of the mouth clicks in post production, but that's what I recommend. And I'm stickin' to it.

Excerpt from threads " Avoiding Mouth Noise " and "Mouth clicks" Dec 6, 2001 at Sound Design discussion list

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