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Make High-Quality Voice Recordings
- 1. Make Quality Voice Recordings with Simple Equipment presented by Robert Hershenow
- 2. Robert Hershenow • Independent TC • Berkeley CA • Senior Member STC • Managing Editor IDL News • Many years in Audio
- 3. Agenda • Good Audio • Bad Audio – Prevention, Treatment • Gear, Techniques • Sources • Q&A
- 4. Good audio is… • Clean • Intelligible • Appropriate
- 6. A recording is like a window
- 10. Three Assumptions • Good script / content • Good narrative voice • Good recorder + knowledge
- 12. Any sound other than the one you are trying to record
- 13. • Environmental • Self-Induced • System
- 16. You have to know you have a problem Before you can deal with a problem
- 22. Self-Induced Noise - Breathing - Mouth noises - Hands and feet - Squeaky furniture - Rustling papers - Loud clothing
- 23. Self-Induced Noise - Listen - Sit still - Use a copy-holder - Use a mic stand - Wear quiet fabrics - Practice!
- 24. System Noise
- 26. Computer fan
- 27. Bad.
- 28. Good.
- 30. The Noise Floor
- 31. The Noise Floor
- 48. Self-Induced Distortion (not loud enough!)
- 52. Any part of the system where gain can change Gain Stage
- 53. GAIN STRUCTURE minimizes noise and prevents distortion. Proper
- 58. Know the STEPS Set the STAGES
- 70. Microphones
- 71. Microphones
- 80. Noise Reduction
- 84. The Levelator
- 85. Recording Software • Learn • Practice • Get a book!
- 86. Headphones • Use closed-ear headphones • Get some cheap ones too
- 87. Tips 1. Count to five, before and after 2. Record ten seconds, then LISTEN 3. Save the first take 4. Never edit the original 5. Use fade-ins and fade-outs 6. Save work as native files 7. Don’t try to replace one word
- 88. Web GEAR Sweetwater.com MIC MFRS Samsontech.com Shure.com Audio-Technica.com SOFTWARE Audacity.sourceforge.net ConversationsNetwork.org/Levelator Books The Book of Audacity - Carla Schroeder Garageband - Missing Manual - David Pogue Acoustic Design for the Home Studio – Mitch Gallagher How to Build a Small Budget Recording Studio - F. Alton Everest
- 89. The Hillbilly Vocal Booth
Hinweis der Redaktion
- Hi everybody, thanks for being here. This presentation is called “Make Hi-Quality Voice Recordings with Simple Equipment.”My name is Robert Hershenow, and I’m (click) anindependent Technical Communicator from (click) Berkeley California and a (click) Senior member of the STC. For the last six years I’ve been (click) Managing Editor of the newsletter for the Instructional Design & Learning SIG. (click) I’ve been creating and recording audio for a long time, and I’d like to share some of what I know about that.
- Here’s our agenda. We’ll talk about (click) Good audio: what it is and why it matters(click) Bad audio and how it got that way, how to prevent it andHow to treat it when it slips through your defenses.(click) We’ll look at gear, both hardware and software, andTechniques for saving time and sanity(click) I’ll recommend a few sources of information & equipment(click) And we should have time for Q&A at the endSo let’s get going!
- What is good audio? Well, the answer is subjective. But as far as voice recording goes, (click) I’d say good audio is clean (that is, free of noise), (click) intelligible (that is, you can understand the words), and (click) it’s appropriate for the situation... Whatever that may be.There’s one word that encompasses all of it for me, and (click)
- … that word is transparent.Good audio is transparent. You hear right through it. It does not distract.
- A sound recording is like a window for your ears. A portal that enables the transfer of information. But if something is wrong with the portal, it can mess up that information.
- For example: this window is distorted. It offers an interesting view – but it’s hard to tell exactly what you’re looking at. What would this sound like if it was audio? Probably confusing. And how about noise?
- Noise is dirt.A dirty window gets in the way. It is a distraction. If it’s enough of a distraction, your attention stops at the window. (And you think to yourself “Man, that’s a dirty window!”) You don’t really see what’s outside because you’re thinking about the dirt.
- But if the window is clean, it is transparent. It is no longer a barrier. So our goal is to create transparent recordings (click) that deliver the message without getting in the way.Because: anything wrong with the audio will grab your listeners’ attention. And as soon as they start thinking about that, they have stopped thinking about what you are saying. Transparent audio frees your listeners to focus on your message. (click) And that’s why quality sound is so important.
- Let’s assume that you have a good script, a good narrator, and a good-enough recording system – and you know how to use it well enough. We will focus instead on two other problem areas…
- Noise (click), and distortion (click).We will look at what they are, how they happen, and how to minimize their effects on your recordings. We’ll start with NOISE.
- There are exactly two kinds of sounds in the world: there’s what you want, and then there’s noise. So… noise is (click) any sound other than the one you are trying to record.
- I’m going to divide Noise into three categories – (click) Environmental, (click) Self-Induced, and (click) System Noise – and then talk about them separately, because they have different root causes and require different approaches.
- Environmental noise comes from all the things around us – people, animals, toys, vehicles, tools, machines, the weather, your telephone… it’s a long list.
- Some environmental sounds we learn to ignore, because we hear them all the time – things like constant traffic, or the ventilation system in the building. In fact, we’ve gotten so used to some sounds that we may hardly hear them anymore. But they are, of course, still happening, and they will show up on recordings, and listeners will notice -- because for listeners, these sounds are out of context. And they will be distracting.
- So it’s important before you start recording, to sit still, be quiet, and actually listen to what is going on around you. (click) Because before you can deal with a problem, you have to know you have a problem. And when you know what you are treating, you can apply appropriate remedies.Let’s try it, right now. Let’s have ten seconds of silence, just sit still, be quiet, and listen. (Discuss)
- So, here are four possible Approaches for dealing with environmental noise, listed in order of probable effectiveness. - Maybe you can eliminate the noise. - Maybe you can reduce it, or reduce its effect on your recording. - Maybe you can work around it by rescheduling your recording session. - Or, maybe you’ll have to relocate – just go record somewhere else.Let’s look more closely at each of these ideas. 7:19
- The first approach is to eliminate the noise. Can you turn the thing off? Or move it into the next room? Can you ask it to be quiet for five minutes, already? You can turn off the heater or air conditioner for a short time. And you can turn off your phone.
- If you can’t eliminate a noise maybe you can reduce its effect on your recording. Close the door; close the window, close the drapes or hang a blanket over the window. Stuff a towel into the crack under the door if noise is getting in.You can point your microphone away from the noise source. And remember that the closer you are to the microphone, the louder your voice will be in comparison to any background noise. We’ll talk more about that shortly.This picture shows an accessory called the Portable Vocal Booth, which wraps halfway around the microphone, and provides some isolation from background noise. It costs about $300. You can do the same thing with a blanket, which actually works pretty well; it just doesn’t look as elegant. I would try the blanket first.
- The Third Approach to dealing with environmental noise is to reschedule your recording session. If you are in a shared space such as an office building, can you maybe record when there is less activity? Before- or after-hours, or on the weekend?
- If all else fails, you might have to Relocate. Sometimes it just makes sense to go somewhere else -- down the hall to an empty office, or down the street to an empty classroom at school or church. How about a walk-in closet full of clothes? How about outside in your backyard at night? How about anyplace where nobody is? How about … fire up your imagination and check out all the resources available to you.How about we move on to the next category, Self-Induced Noise?9:43
- Which is all the noises you make yourself by doing all the things you do. (Click) Here’s a partial list.It’s easy to overlook many of our own sounds. We’re accustomed to hearing them and they coincide with our actions. I don’t hear myself breathing most of the time, but the microphone does. And, if you drop something on your desk, you expect it to make a noise – when it does, you’re not surprised. But if that noise ends up on your recording, your listener will be very surprised – they didn’t drop the thing, and they didn’t see you drop it. So the noise is unexpected, and will be a distraction.My friend made a training video for her company, and only after she recorded the narrative track, did she realize that her earrings – which she had been wearing all day – were jangling through the entire thing. And she had to do record all over again.
- Once again, the most effective thing you can do is to pay attention, and listen. (click) Listen to the sounds you make. You have to sit still and control your breathing and movements while you’re recording. (click) It is hard to do, but gets easier with practice.(click) Use a copy holder or a music stand to hold your script, or set it on the desk, so you’re not handling papers. (Demonstrate) which are noisy.(click) If you don’t use a headset microphone, use a microphone stand. Don’t try to hold onto the mic – (demo) this is called handling noise and it’s very distracting.(click) When you record, wear clothing made of soft fabric, like cotton, that doesn’t make noise when you move. And of course, (click) Practice your technique... Record it, listen to the results, and modify your approach as necessary.OK, that’s it for Self-induced Noise. Now, let’s look at System Noise.
- System Noise is noise generated within the recording system itself.All electronic devices generate some electronic noise, but if your system is properly set up (which I’ll talk about in a minute) you shouldn’t have to worry about that. What is more likely to bite you is alarms and alerts from your computer, feedback from your speakers, and the sound of the cooling fan.
- So while you’re recording, turn off system sounds. I got tired of doing this every time, so I created a separate user account for recording. When I log on as the recording guy, system sounds are disabled; I don’t have to remember to do that. It’s handy.
- Pay attention to your computer’s fan. It will come on, and your micwill pick up the noise. (click) So keep your microphone as far away as possible, and point it away from the computer.You might even find it helpful to hang a sound-absorbent barrier, like a nice heavy red velvet curtain (click), or, you know,a blanket, between the computer and your microphone to knock down that noise. Just make sure you leave room around the computer for cooling.
- Here’s a tip: don’t run audio cables (like this microphone cable) alongside AC power cords. Because, the alternating current in the power cord can induce hum (click) on the microphone signal. This is a bad thing, so keep them apart. I try to keep power cords on one side of the desk and audio on the other, whenever possible.
- When you have to crossthose wires, try to arrange them at 90 degrees, (click) which will minimize interaction between them.
- And, did you know that many dimmer switches spew electrical radiation all over the room? Your recording system can pick that up and reproduce it as noise. If your audio has a buzz on, that might be why. Either turn these things off completely or go somewhere else.
- One last thing about noise: Despite all this care you’re going to take, there will always be some [click] noise present on your recordings. That’s these dots down here. If you have done a good job, that noise will be much quieter than your program material (that’s the white squiggly line up here; see, it’s up here because it’s louder). When noise is low like this, it’s pretty much inaudible.
- The level of this ambient noise that we can’t ever quite get rid of is called the Noise Floor, because that’s as low as the volume of your soundtrack can go without running into the noise. And we’ll come back to this concept in a few minutes when we talk about Gain.But first, we’ll take a look at Distortion.
- Which is a misrepresentation of the original sound. A change in its character. This happens for different reasons, and it isn’t always bad – tone controls, by definition, distort the sound. For good or ill. Anyway, we can divide Distortion into the same categories we used for Noise. The first is Environmental Distortion…
- …which is what happens to sound in an enclosed space. Every room sounds different. Big rooms usually sound better than small ones. Singing in the shower sounds different than singing in the living room. For one thing, the rooms are different sizes, but also they are covered with different surface materials.
- Hard, smooth surfaces like tiles and walls and windows reflect sound waves...
- which bounce around …
- Until their energy dissipates. And, all these sound waves bouncing around and running into each other change the sound you HEAR, sometimes in good ways and sometimes in strange ways. But in general a reflective room is very lively, with all that sound bouncing around. Think of clapping your hands in an empty warehouse or gymnasium, how it reverberates.
- Hard surfaces that are curved or irregular – for example, a bookcase full of books – will refract the sound, break it up, send it off in many directions at once, causing it to dissipate more quickly. This is still lively-sounding, but not as much. A good way to tame a lively room, in fact, is by putting some stuff in it. Fill that gymnasium up with people, and it doesn’t echo so much.
- Soft surfaces like carpeting, upholstery, and clothing absorb and trap sound energy. This can soften or deaden the sound to varying degrees.
- So each of these properties – reflective, refractive, and absorptive – do different things to the sound. Most good-sounding rooms contain multiple surface types, and different places in the same room often sound very different from each other because of it.
- So it’s important to try different rooms, and different places for the microphone within the same room.
- So record your voice in different locations.
- Then listen to the recordings…
- to see what sounds best. If none of them do, try another room.
- I almost always end up standing in a corner, with a microphone a few feet out, so that it faces the center of the room and I face the corner as I speak into it. I’m maybe 6 or 8 feet from the corner, myself.I am not directly facing a wall, and neither is the microphone, which considerably lessens the effects of room’s acoustics.That usually means a more transparent recording. This will work nicely with any kind of microphone. And, it works in almost any room. Any questions on environmental distortion? Let’s move on. 24:00
- Self-induced distortion is often caused either by speaking too loudly into the microphone, or by turning something up too far, either of which can overdrive the system. The key is practice. The more familiar you are with your recording system the easier it will be to produce consistent sound levels. And, you always have to pay attention: listen, and watch the level meters. They tell you how loud the sound is. These are analog meters. The needle swings from left to right with increasing volume levels. If it hits the red part, the sound is distorting. Sound levels fluctuate so the needle will bounce around, but you want to keep an eye on how high it goes – the peak volume levels.
- Here’s a digital meter, showing an example of good peak recording levels. Not too loud, but not too soft. Again, if the meter is in the red, it’s too loud. These red lights are all off, which is good, but most of the green lights are on, which is also good.
- This sound, on the other hand, is too loud. Those red indicators tell you so. You can either turn it down, or don’t talk so loudly… because this sound is distorting.
- Now, only a couple of the green indicators are lit. If this is a peak reading, this sound needs to be louder, because this recording is going to be noisy. I’ll show you why in a moment. That wraps up Self-Induced Distortion, which basically, is about being not too loud.
- And as for System Distortion, this slide is blank –because if your equipment is in good shape, System Distortion should not be an issue.
- And that’s what I have to say about Distortion, a misrepresentation of the sound. …Which means it’s time to move on to our discussion of GAIN. 26:00
- What is GAIN? It is (click) a measure of amplification. As in: how much louder or softer did the signal become, between one point and the next. So, Gain can be positive or negative, depending on whether the sound level got louder or softer. If it stayed the same, it’s called “unity gain.” Just so you know.
- A gain stage is any part of the system in which the gain can change. Even the simplest system has at least a couple of gain stages. The first is your voice (you can talk louder or softer). The second “gain stage” is the microphone pre-amplifier, which may be in the microphone itself, it may be a separate component, or it may be part of the computer. It may have a control, or it may be fixed.Your recording software may also have an input adjustment control, and perhaps there is a Master recording level as well.Each of these places represents a gain stage. For the best sound quality, you must optimize each stage sequentially, starting at the beginning, with your voice.
- Gain Structure is the term that describes all those settings in series within your recording system. (click)Proper gain structure is very important, because it minimizes noise and prevents distortion. Here’s how that works.
- Each stage of your system has an ideal range. It can handle a certain amount of sound.The trick is simply to keep the sound within that range in each stage. In the case of your voice, that means you don’t yell, and you don’t whisper – you keep it in-between; you talk normally. And then you just do the same thing for each gain stage: using the meters – or, if you don’t have meters, using your ears – you set each stage to its ideal level, then move on to the next stage.
- Now above that ideal range, the sound is too loud, and it causes distortion.
- And below that ideal range, the sound is harder to hear (and if it’s really soft, it approaches the noise floor). If I record like this, with the sound down low, someone is going to turn it up later on – if not me during editing, then my listener during playback – in order to hear it better.The problem is, if I recorded this, my voice and the noise just below it would be locked together in that recording. No longer separate things, they are one hunk of sound.So when I turn it up so I can hear my voice, or when the listener turns it up …
- …the noise comes up, too. And now, it’s not that transparent dinky below-the-noise-floor noise any more. It’s loud now. And that’s why setting gain structure is important.
- So if you don’t know where all the level controls are in your system, find out. If you don’t know where the meters are, find out. Explore it. Check the help files, check the forums, ask your people. Hit the library or the bookstore.I know this sounds complicated, but it makes a huge difference. And after you go through the process a few times and start to understand it, it won’t take very take long, (especially if you write down what you did each time). And every time you do it, it will get easier.
- The first step in setting that Gain Structure is microphone placement. We talked earlier about microphone placement within the room; now, let’s talk about it in relation to your face. And this may apply even if you use a headset mic…
- The idea – as always – is to maximize signal (your voice) and minimize noise. So you want the mic up close, to capture your voice at a good strong volume, but not so close that it picks up things you don’t want, like mouth noises.
- Contrary to what we see on television, the right place...
- … is NOT directly in front of your mouth, but rather...
- ... off to the side and a little below your mouth....
- So that the air from your lips can pass over the microphone rather than blasting straight into it. So you can say something like “Please pass the popcorn” – if you wanted to – and nothing bad would happen.
- A good starting point is between four and six inches away from your face, pointing directly at your mouth, but not right in front of it, instead just below and to the side of your mouth. The ideal distance away from your mouth will depend on how loud your voice is – but the closer the microphone is, the stronger the stronger your voice will be – theoretically allowing you to turn down the input level a little, which lowers the level of ambient noise that you’re putting into your recording.Does that make sense?
- A pop filter can help. You should have one. It is mesh screen that mounts in front of the microphone to knock down those blasts of air before they hit the mic. Pop filters work, they can help you relax a little in front of the mic, and they’re not necessarily expensive (though some are).
- Or you can make your own pop filter by stretching a section of nylon stocking over a hoop made from a wire coat hanger; this is probably not even as attractive as it sounds, but it works.
- Since we’re already talking about gear, let’s talk about GEAR!
- Buying a microphone is a balancing act. What do you need? What do you want? Often those are different things. What’s the budget? And what other considerations should you take into account?Will you only use it to record narration? Then you might like a headset. Will you have to share it with anyone else? Then you might not like a headset. There’s something called the yuck factor, which comes into play…You should buy the best you can afford, but there’s no sense in throwing money away on something over-the-top. Will your recordings end up on a CD? Or are they designed for Captivate training to stream on the web? If they’re not going to be on a CD, maybe you can save a few dollars on the microphone. And what about portability? Do you need a little microphone that you can move quickly? These are all questions which could affect your purchase.
- If you record with a computer, a USB microphone is the way to go. It doesn’t need any other parts, except maybe a stand. You simply plug it in to your computer’s USB port and it’s ready to go. A USB headset microphone is the easiest to use, because once you put it on it stays in place. And most USB headsets come with built-in noise-reduction circuitry, which can make your job even easier.
- You can buy a decent USB microphone – either headset or otherwise – for not very much money. This one, the Samson Go Mic, is about $39 right now. And it’s a pretty good little microphone. I’ve seen decent headsets in the same price range. Of course, if you spend more you’ll get better stuff. Personally I wouldn’t spend any less.There’s a whole lot more to say about microphones, but I don’t have time to do it. So at the end of this I’ll provide links that offer more information, or if you want to come on up afterward we’ll talk.
- You also have choices when it comes to recording software. There’s Garageband for the Mac, which is a great program, very easy to use, and you can buy it from Apple for $15. You almost can’t beat that price. Except maybe…
- ...for this program, called Audacity, which is free software available from Sourceforge.net for PC, Mac, and Linux. Personally, for the Mac, I prefer Garageband; it just works better for me. But Audacity performs very well on the PC, and I use it all the time.Now let’s talk about editing and sound manipulation.
- What happens if you record something perfectly but there’s noise in it? Maybe you can fix it. Filters are special tone controls. Most recording programs have them. Filters let you zero-in on a problem area and make precise adjustments. For example, if your track has high-frequency noise, you could remove it or at least tone it down with a low-pass filter. (click) Which passes all frequencies below a certain point in the audio spectrum and rejects frequencies above that point. It’s like a treble control, except that you can set that cutoff point yourself.(click) A high-pass filter is just the opposite; it rejects low frequencies and passes the higher ones. (click) And a notch filter takes a chunk out of the middle which can sometimes make a weird-sounding recording sound more natural. Or vice-versa.
- Here’s how a high-pass filter can improve a recording with some rumble on it; maybe from a train or a truck going by.
- This filter works in this circumstance because your voice occupies a different part of the sound spectrum…
- …than does the rumble. So you can set the high-pass filter to …
- … split them apart, at a point that spares your voice…
- but eliminates – or reduces - the rumble! Filters are helpful in all kinds of noisy situations, and I urge you to explore them.Although it’s better in the long run to prevent or reduce the noise up front than it is to try to deal with it later, sometimes you don’t even know the noise is there until later, and then you’ll be happy you have these tools. So get to know them before you need them.
- Noise Reduction software is likean automatic filter. Essentially, you give it a sample of noise…
- ... which you have selectedin your recording’s waveform …
- ... Then you set some parameters …
- ... and it removes everything that looks like that noise from your recording. Like the other filters, Noise Reduction takes a bit of fine-tuning to get just right, but it is worth the effort. Check it out.
- One piece of software I recommend highly is the Levelator. I don’t know exactly what it is and even the program’s website doesn’t say what it is. But it works.You open it on your desktop and drag-and-drop an uncompressed audio file onto it. The Levelator churns out a new file that just sounds better. That’s all there is to it. It’s easy. Levelator is a free download for Mac or Windows.
- As with any software, there is great benefit in getting to know these tools so they can help you do your job, and not get in the way. Have I mentioned this?Learn, practice, and practice. Especially, practice. Especially, before you have to record a big project.And take advantage of other people’s knowledge. Buy a book. David Pogue has written a lot of them. I’ll give you some recommendations.
- Don’t record with speakers turned on, because they can cause feedback and echo. If you don’t use a headset, I recommend closed-ear headphones when recording, because they don’t bleed through into the microphone. Earbuds will work fine, too, though I don’t find them as comfortable.Ideally you’ll have a pair of good, comfortable headphones for recording and some cheap ones too, because that’s probably what your listeners will use, and you’ll want to be able to hear it the way they will hear it. You might also want to check the sound on your laptop speakers for the same reason.
- Finally, here are a few tips that can save you some misery. Finally, here are a few tips that can save you some misery. (click) Count to five… after you start the recorder but before you start speaking, and again after you finish but before you turn it off. In the heat of the moment it’s easy to cut off the beginning or end of your first or last word, and you can’t get that back. It’s easy, though, to edit that extra space out of your recording. If you’re a really nervous type, count to ten.(click) When you first start a session, Record ten seconds of your work and then LISTEN… More than once I have finished recording only to discover that the mic was turned off. And the first take is almost always the best, so don’t miss it.(click) Save the first take. Even if you think you can do better. Because you might not.(click) Never edit the original recording. Make a backup and work on that. (click) Use fade-ins and fade-outs when you edit, rather than hard cuts. They will sound more natural. Look in your book that you bought to see how to do that.(click) Save work as native files… even if all you need is an MP3. If you need to go back and change something later, it will be easier and quicker.(click) If you discover at some later time that you need to fix something, don’t try to fix just one wrong word. It is very difficult to match the sound of a previous recording, and your correction will stand out. So do a whole sentence over, at least.
- Here are links to some of my favorite audio things. You can get this from Slideshare too or Summit@AClick, so you don’t have to write them all down.
- Thank you very much. I hope you enjoy the rest of the Summit!