Eva Amsen has written in her blog about the usual ills of seminars. Come on, y’all know what I’m talking ‘bout. The lights are low, but there’s scant promise of romance. The parade of slides is endless, and all are crammed with so much data that they might as well be written in Old High Transylvanian (I once used ‘Medieval Bulgarian’ as the epitome of the recondite and esoteric, until I met someone who was an authority in, you guessed it, Medieval Bulgarian).

And worst of all (and this is what really got up Eva’s nose) is that the lecturer is addressing the slides, not the audience. Not only is this the height of bad manners, it shows that the lecturer is using the slides not to edify the audience, but to tell herself (it was a ‘she’ on this occasion) where she is in the lecture – a sure sign of inadequate preparation.

I have found through long experience that any powerpoint presentation can always be reduced by one slide, and have taken this to its logical conclusion. So, when I give a lecture, I rely on as few A/V props as possible. All I need is a mite of preparation, maybe a few notes – and, if the theater is large, a microphone. A radio mic is best, as I can roam around the stage and even into the audience.

In recent years I have even largely dispensed with the lecture and let the audience do the work: I am a firm believer in leaving the often-promised but rarely delivered time for discussion. And when I’m on the stump as a Nature editor, talking to scientists, there are always plenty of questions, anyway, as you might imagine.

If talking with one’s back to the audience is what irritates Eva Amsen, the thing that drives me round the bend and up the wall is poor microphone technique. Either the lecturer refuses to acknowledge the existence of the microphone (and so is often inaudible), or spends the entire lecture confusing it with an ice-cream cone in imminent danger of melting, so the audience is treated to booming feedback and an overly intimate display of the innermost thoughts of the lecturer’s tonsils.

Matters are not helped if the conference organizer has no idea how to work a public address (PA) system, if no technical support can be found. And it’s amazing how many conference venues have PA systems that are either inadequate, or so complicated that no specialist in Old High Transylvanian would be able to work it without going on a training course.

Where did I learn microphone technique, and some of the rudiments of using a PA system? Ah, well. Perhaps my misspent youth (and early middle-age) in rock bands was not as misspent as I first thought.

So, here are a few tips on using a microphone.

1. It won’t bite. If possible, practice a little, so that you can use the microphone without being conscious that it is there at all. For this purpose, a tie-clip mic attached to a radio pack is best, as it is completely unobtrusive.

2. There is no need to shout. You should be able to speak in a normal, conversational way.

3. Get the distance between your mouth and the microphone just right. About 20 cm is fine. The trick is to get it close enough that the audience will hear your voice uncontaminated by any other ambient noise; but not so close that your tonsils, lips and tongue add their own contributions. And nobody wants to use a mic after the previous lecurer has gobbed half their lunch over it.

4. Where possible, practice beforehand (see point 1). Get to know the sound technician at any venue by name – these people are there to help you. An important part of practice, especially if you have a roaming mic, is walking about the venue to find any dead spots, or places that generate feedback.

5. On the Subject of Feedback. Microphonic feedback happens when the microphone picks up the signal coming through the loudspeakers, amplifying it so that it goes through the loudspeakers again, the reinforced signal picked up by the microphone, and so on ad infinitum, and before you can say ‘positive feedback loop’ you have that horribly penetrating squealing howl. Feedback is exacerbated if the microphone is turned up too much, and/or the microphone is placed in front of the plane of the loudspeakers. It can also happen in poorly designed acoustic spaces, and can be eliminated using a piece of equipment called a graphic equalizer, which homes in the particular frequency range most responsible for the feedback effect. This is beginning to get technical – which is why you need to make friends with the sound technican.

In conclusion, and as I am always tempted to say when talking about Tolkien, Elvish Has Left The Building.