How to optimise presentations or talks at KEX
How do human voices interact and circulate at KEX?
“The circulation of sound is, of course, complicated as it travels in all directions with millions of reflections. The sound behaves a bit like jelly: It is vibrating and if one puts it on the table it will take some time until it wobbles to a complete halt.” PB
The best position for delivering a speech at KEX is, accordingly, in the middle of the room, two or three meters away from the wall facing the French balcony, because the distance between the two opposite walls is shorter. This also forces people to stand closer to the speaker. Secondly, this positioning reduces the possibilities of reflection.
“If you address somebody facing the balcony, you have the largest openings and windows facing you, which will let the deep frequencies through like a knife through cheese. If I play a tambourine here, a low sound, part of the waves will just pass through the window. The glass of the windows will however reflect high frequencies. When you have people standing closer to the wall, the strength of the reflection is once again reduced.”PB
Note to a speaker:
Articulation is what counts the most. The best speech would be spoken slowly with a lot of gaps – the language should be a good mixture of vowels and consonants. This is a question of clarity of voice as much as of reverberation. If a child, an adult female, or adult male speaker are trained and articulate equally well, the child might be the best choice as speaker, but not for the reason one can imagine. When a group of people is speaking in the same frequency, the first thing to do is to produce frequencies different from the ones you do not want to hear. At a children's party an opera singer with a low voice would be the best choice. If an audience is composed of people with low voices, the speaker should preferably have a high voice… and the other way around.
One can also use the mobile elements to improve acoustics:
“If you stand speaking in front of them, they will reflect your voice. If you place the walls like a V or cone behind you, you can emphasize the direct sound and the first reflection of your voice (or any sound produced). So for a clear sound, standing inside the V would be perfect.”PB
The created resonance would be under 18 milliseconds in that case, which would enrich the sound.