If you have seen Ted Lasso you may have noticed these unusual microphones used by the football commentators.
Despite being a microphone nerd, I had never seen anything like them before. So I decided to go into research mode and discovered these microphones are quite fascinating.
They are called "Lip-Ribbon" or "Commentator's" microphones.
They were specially designed by the BBC in the 1950s for extremely noisy environments. Soccer Football stadiums have peaked at 130 decibels so they needed something that would not get overwhelmed in that circumstance.
They use several very clever techniques to make sure only the voice is picked up and everything else is rejected.
First, they use a bidirectional polar pattern.
That means it will accept sound from two directions, but reject any sound coming in from the sides. And since the diaphragm is only exposed on one side, that helps reject sound coming from the other direction.
Next, the microphone is not very sensitive so you literally have to hold it up to your lips (hence "lip-ribbon") in order for your voice to have enough sound energy to vibrate the diaphragm.
That top part rests directly on your lip and there is a little pop filter to keep your plosives in check.
There is a built-in high pass filter so it rejects any sound below the frequencies typically used by the human voice.
But my favorite trick... a labyrinthian internal baffle system.
(I found a diagram of this when researching but then I lost the tab and I cannot find it again. So you'll just have to accept this crude photoshop I did in 30 seconds to help you understand.)
Sound is energy. And that energy is diminished the farther it travels. The inverse square law for sound states that the intensity of sound decreases by approximately 6 dB for each doubling of distance from the sound source. Sound also diminishes when it reflects off a surface.
That is a very sciency way of saying... make sounds go through a tiny maze and only sounds with the most energy will prevail.
So if you have your lip pressed up against the front of the mic, your voice's energy will make it through the labyrinth of baffles without issue. But every other sound in the stadium will have a much harder time getting through.
These mics may even be vuvuzela-proof.
And even more amazing... this microphone was designed in the 1950s and they have yet to create anything better for incredibly noisy environments.
