By Enti Bracamonte
Posted: August 5, 2022

Microphones
and how to use them

There are many—MANY—types of microphones, and they all have specific ways in which they like to be treated. As a rule of thumb, speaking at a distance of 10 to 15 centimeters (4 to 6 inches) from a microphone is considered adequate/safe in most situations, but the fact remains that different microphone types have different requirements, and while some can tolerate high sound pressure levels—as is the case with dynamic microphones—other types, like cheap electrets, tend to clip (distort) if you blow air into them or if you speak too closely or too loudly— but we will come back to that in a bit.

It may well be that I may not even have to say this, but I will, nonetheless, just because this would not be a proper article on the use of microphones, if I didn’t: A golden rule that can keep you out of trouble, if you apply it, or sink you to the bottom, if you don’t, is “always treat a microphone like it is on.” We have all heard the stories, let’s make sure our names don’t get added to the list.

So… Maintaining the proper distance from a microphone is crucial, all too crucial, and, so, we have to speak at length about the consequences of getting it wrong:

First and foremost…

In live, high-volume situations, such as concerts, singers can often be seen pressing their lips against the microphone. This is done to prevent feedback, but requires some signal processing. Never press your lips against the microphone, if you are a conference interpreter, it will sound horrible to your audience (unless you have the right setup), but, more importantly, it is not a very hygienic thing to do, if you are using somebody else’s microphone. I don’t mean to gross you out, but microphones are excellent spit collectors, which is precisely why most professional audio gear stores do not allow microphone returns. Always maintain a healthy distance (10 to 15 centimeters or 4 to 6 inches).

On the other hand, if you are interpreting from a meter away, your microphone will receive more reflected sound than direct sound and your audience will perceive your voice as recessed or, worse yet, your voice may sound annoyingly on par with any ambience noise present in your booth. Also, in wanting to hear you better (while you speak into your microphone from too far away), your audience will have a natural tendency to raise the volume on their receivers and will, very likely, hear everything they aren’t supposed to, such as—and this is by no means an exhaustive list—your laptop’s fan, the rustling of papers, the creaking of your chair, the bouncing of your leg, burping and farting (yes, feel free to read that again), the cracking of your knuckles, that whispering conversation your partner is having on the phone, or—more damaging still—the smart-ass comment your booth partner has decided is too funny and can’t wait to be said, even though, CLEARLY, you ARE speaking into the microphone, so, CLEARLY, the microphone is ON, but, still, the smart-ass comment cannot wait. Now, if none of these things apply to you, then, congratulations are in order. All too often, however, I learn about yet another case of microphone indiscipline.

If, on the other hand, you find yourself a victim of your booth partner’s misconduct and lack of finesse, while you are interpreting, just point them to this article and let me do the talking for you; there is no need to get confrontational about it and, potentially, sour what could, otherwise, be a perfectly good partnership—maybe.

And while we are on the subject of microphone indiscipline… please forgive me for stating the obvious so bluntly: the interpretation booth, while comfortable, insulated, and quiet, is not a confessional; quite the opposite is true, in fact. The interpretation booth is not meant to safeguard your conversations, it is meant to more clearly disseminate what you say, so resist the temptation of discussing your secrets in it. If you want to have a private word with someone, it is safest to just leave the booth and go to a place without microphones.

On their own, microphones cannot correct or compensate, in any way, for what you do in the booth; they are just instruments, and it is your job, as a professional, to learn to use them well. Some signal processing can be applied to what comes out of your microphone (that is, again, if you have the right set up), but there are limits to what can be achieved.

Please understand that, while Earth’s atmosphere—on account of its very low density—provides for very weak sound coupling between your mouth and your microphone, the surface of your desk, on the other hand, is an excellent conductor of mechanical noise. If your microphone is sitting on your desk, anything you do on that surface will reach your microphone unimpeded. Always strive to insulate your microphone and any source of mechanical noise from any surfaces they may be sharing. If your cellphone is set to vibration mode, for example, do not place it on the same surface your microphone sits on—or, at the very least, place your cellphone on a sponge or thick piece of cloth (even a folded napkin will do!).

Carefully managing ambient and mechanical noise, in your booth, and keeping the proper distance from your mic will go a long way in making you sound like a professional newscaster, but that is only one part of the equation; your microphone will still require a lot more help from you, in order to make you sound good.

If you are a conference interpreter, you should not be speaking into your microphone like you are having a telephone conversation, for example: you should not whisper, you should not mumble, you should not yell, and you should not be speaking hurriedly or breathing into your microphone like you are running a marathon. If you are gasping for air, after a very long sentence, either use the “cough” button or make sure you move your head away from the microphone momentarily, while you replenish your lungs. If you are a heavy breather, make sure you place your microphone slightly off to one side of your mouth and nose so that you are not breathing directly into it. Your mic should still be aiming at your mouth, however, especially if it is a cardioid (directional) microphone; otherwise, the output of your mic will have off-axis coloration and your audience will hear more reflected sound than direct sound, which will likely affect intelligibility. This is especially important if your booth is poorly designed or lacks acoustic treatment.

Most sound technicians will tell you: “If no one noticed the sound, the sound was good.” This holds true for concert venues or lecture halls, and what you don’t do with your mic is just as important as what you do with it. Keep yourself from becoming a source of noise. Avoid becoming a distraction. Strive to let your voice be the focus of the audience. This, alone, will bring you big rewards sooner than later.

If you are a conference interpreter, you should always make a conscious effort to speak calmly, clearly, and cleanly. No chewing gum, no candy; there should be nothing in your mouth that may cause you to salivate. Rinse your mouth with plain water before you begin interpreting, if you must. Salivation noises are very annoying and switching candy from one side of your mouth to the other is even more so. Always concern yourself with how you may be coming across to your audience; always put yourself in their shoes, I cannot emphasize this enough.

And before you start thinking that this is all unrelated to microphones, let me tell you: professional use of a microphone starts with a certain etiquette that not a lot of people seem to have clear notions about. Proper conduct when using a microphone is something that cannot be overstated.

Now, where were we?…

Always ask for a soundcheck, especially, if you are not a regular at the venue you will be working in. Bad sound can affect your professional image, particularly, if your voice sounds lowest of all. It is best to keep all levels in check. Have someone listen for volume levels and noise before you start. Noise and wild variations in volume levels, across different microphones in a venue, can prove too distracting not only for the audience, but for you, as well, if you are having to constantly adjust the volume setting of your headphones.

A microphone that is not only loud, but also overly sensitive and able to, all too clearly, capture lip smacking or any other subtle sounds very loudly, while you are maintaining the proper distance from your mic, might be an indication that a compressor setting is ON, somewhere in the audio chain, and you better turn that down if you do not want complaints from the audience.

In a way, an audio compressor is to our hearing what a telescope is to our sight. A compressor brings softer, more distant sounds closer to our ears while also keeping loud sounds from becoming too loud. A compressor forces varying volume levels to remain within a certain range of intensity for a more consistent listening experience.

Because of the, by now, well-established fact that we, humans, are… well… not machines… we do tend to slightly vary our distance from the microphone or the sound level of our voice, and, so, most conferencing systems—those with built-in interpretation capabilities, in particular—use compressors in order to keep sound levels consistent. Have somebody speak into your microphone while you listen, and be sure to bring it to the attention of the sound technician if you suspect an excessive compression setting is being used.

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FYI:

A typical, useful compression setting for a conferencing/interpretation system might be a 2:1 or even a 4:1 ratio. A 1 to 1 compression ratio (1:1) means no compression at all, while a 10 to 1 compression ratio (10:1) will prove excessive for spoken word applications.

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As a matter of daily routine, my wife and I always listen to one another, when we are working. We monitor each other, right at the start and at random times, during the day, just to make sure that our volume levels are good and that our sound is clean. If something’s wrong with the sound, we want to know it first.

You may be thinking, as you read these lines, that some of the things I am saying here are the responsibility of a sound technician and not the interpreter’s, but remember: it is your voice the audience is listening to, and it is in your best interest to let nothing interfere with your effective delivery of the message. Also, being a professional means caring not only about your performance, but also about the overall success of the event you are participating in. Lastly, the things I’m talking about here can be easily taken care of before you start interpreting, and the sooner you can uncover a problem, the more quickly it can be addressed, without detriment to you and, hopefully, without the event coming to a grinding stop soon after take off. On to microphone types, now…

A vast variety of microphones does exist, and I cannot possibly tackle this topic in full, first, because—I’m not ashamed to say—I do not know everything there is to know about every type of microphone out there; and, second, because not every type of microphone is relevant to what we do, as simultaneous interpreters.

Even if I could encompass the full gamut of microphones in this article, it would obviously take a long, long, time to cover it all. You don’t have the time; I don’t have the time, so I am limiting the scope of this article to only those concepts that have served me well, as a conference interpreter, hoping that they will also be helpful to you.

The main thing you have to know about microphones, as a conference interpreter, is that they come in different form factors that can have different polar patterns (directionality) and use different transducer types. A transducer is the element that converts the changes in air pressure into electricity. How the type of transducer and polar pattern affect your work, as an interpreter, is very important, and it is precisely what we will be looking at next…

— Polar Patterns —

The polar pattern of a microphone refers to how directional it is, meaning how sensitive or receptive a microphone is at various degrees.

Omnidirectional microphones capture sound equally well from all directions and are preferred in situations where noise is either not an issue (as in a recording studio, for example) or the very thing that needs to be captured (nature, the cheering crowd in a stadium, etc.).

But use an omnidirectional microphone in a small, confined, acoustically-untreated space and the echo effect will be overwhelming. The microphone will pick up just as much reflected sound as it will direct sound, and will do so from all directions!

Although omnidirectional microphones are a nightmare to work with in live-sound applications or in small, untreated acoustic spaces, one big advantage to working with them, if you can get away with that, is that they have no proximity effect. You really can get very close to an omnidirectional mic, and the sound will remain natural; there will be no boost in the lower frequencies as you get closer.

Cardioid microphones are so called because their polar pattern can be though of as having the shape of a heart that narrowly envelops the front of the capsule. Cardioid microphones are designed to be more sensitive to sounds coming from the front. The benefit of using cardioid microphones is that they are less sensitive to the reflected sounds that reach the microphone from disadvantaged angles, which helps reduce the “echo” effect in small, untreated acoustic spaces where an omnidirectional microphone would fail miserably.

But the “echo cancelling” convenience of cardioid microphones comes at a price, of course, and that price is “Proximity Effect.”

While you can get as close as you may like to an omnidirectional microphone and not experience any sound coloration (change in tonality), due to proximity, a cardioid microphone is unforgiving: lower frequencies (bass) build up very quickly as you get closer to the microphone, thereby, giving your voice an increasingly nasal quality and causing more “plosives” to occur. Unless you have the right set up, maintaining the proper distance is crucial for intelligibility when using cardioid microphones (no less than 4 inches, and no more than 6).

Although cardioid microphones are more sensitive at the front of the capsule (the business end) that does not mean they will not register loud enough sounds coming from any other directions. Loud enough sounds will still be heard.

— Transducer types —

Dynamic microphones

As I said before, some microphones can handle higher SPL (Sound Pressure Level) better than others. Dynamic microphones, for example, regardless of form factor, handle high volume levels exceptionally well: you can scream into them, at the top of your lung, they will not flinch. You can place them facing kick drums, you can place them facing loudspeakers, you can place them in the engine compartment of a race car (this is not an exaggeration), they will not fail; their signal will remain healthy and clean.

Hand-held dynamic microphones can be easily recognized because of their size and shape: they look like ice cream cones, in general, and have some sort of metal grill, on the “talking end,” to protect the capsule from physical damage. This protective wire mesh also doubles as a “pop” filter that breaks up “plosives.” Plosives are sounds that, by compression of your lips, push air forward, into the microphone. Left unchecked, plosives can be quite disruptive and will affect the intelligibility of your speech.

Condenser microphones

Professional condenser microphones are the sophisticated siblings of the tough, dynamic microphone. For the most part, hand-helds have the same basic shape (ice cream cone) and share the same tolerance to high sound pressure levels, but are far more nuanced.

Unlike dynamic microphones, the condenser microphone requires an external source of voltage called Phantom Power. For your purposes, as a conference interpreter, however, you can treat condenser microphones as you would dynamic mics; they can take any SPL your lungs can generate.

Electret microphones

Electret microphones are the finicky cousin of the condenser microphone. Although the technology has made considerable progress and some electrets can be very good and very expensive, for the most part, due to their small size and design simplicity, electrets are usually found in cheap or small electronics, such as cheap computer headsets, cellphones and tablets, camcorders, doorbell intercoms, communications radios, etc.

Electrets are far less tolerant of high sound pressure levels, and you really need to keep your distance for intelligibility: make it 15 centimeters (6 inches), rather than 10 (4 inches), just in case, especially, if you don’t see a windscreen on the microphone. If the microphone is tiny, or the space it sits in is tiny, you can just assume it is an electret; be mindful.

In the realm of simultaneous interpretation, electrets are more likely to be found in portable transmitters than in interpreter consoles in a booth.

Boundary microphones

The boundary microphone is the bastard child of… just kidding, I am done with the family tree analogies, I promise. I, actually, wasn’t even going to talk about boundary microphones in this article, but I realize, now, that I did find myself facing a boundary microphone, many times, in my career, as I sat through board meetings while some of the attendees listened in, over the phone, from other parts of the world.

A boundary microphone is actually a condenser microphone that [usually] has the shape of a wedge and is placed on a flat surface, such as a table or [even] the floor, in order to take advantage of surface reflections.

Because they are, in fact, condenser microphones, these unassuming little guys are pretty tough and can handle very high sound pressure levels. Getting a boundary microphone to distort, is harder than hitting a high note on a tuba—you really would need quite a proper set of lungs to make one clip. This is the one case in which distance is not actually a factor for you, but, for the sake of clarity and intelligibility, you, as the interpreter in the room, should sit—or stand—facing the microphone. Where microphone and loudspeaker may be too far apart, however, always prefer the place where you can hear more clearly, and just make sure you are projecting your voice for everyone in the room to hear. If everyone in the room can hear you clearly, so will the boundary microphone.

Remember…

Transducer type and polar pattern are two different things, and any transducer type can exhibit any polar pattern.