What makes a good scream?
Scientists in Salford are trying to find out what makes a good scary scream.
As part of their research they've set up a special chamber where people can go and shout at the top of their voice.
Ricky's been along to find out why...
"The anechoic (or no echo) chamber in Salford University is a very strange place.
The walls are covered in big, spiky blocks of grey foam and when you enter you close a big door behind you that's also covered in the sharp chunks of odd looking sponge.
What's even weirder is that there's no floor, just a sort of springy wire mesh you can bounce on and below, you guessed it, more foam!
Find out more about the 'scream chamber'
It's designed to cut out all noise apart from what's going on in the room - a bit like music studios where pop stars record their songs.
When you enter there's total silence.
This is pretty odd as usually, no matter where you are, you can hear something - even if it's only a distant road or the sound of birds singing in the trees outside. But inside here it's completely soundless and there's no echo at all, and your own voice sounds very flat.
The researchers here study sound and any noise from outside the room could ruin their experiments so the anechoic chamber is very important to them.
Ricky and the kids having a go
One thing they're looking into at the moment is screams and what makes some screams scarier than others.
It's part of the Manchester Science Festival and researchers are keen to work out what it is about a scream that makes it frightening to listen to.
Professor Trevor Cox has been conducting the research. He thinks there are a couple of things that make screaming scary.
The key one is whether the person that hears the scream really thinks the screamer might be in trouble. That makes it scary as you'll be worried for the person screaming and for yourself too!
Which presenter screams the loudest?
The screams that really make you think that someone is danger happen when the screamer really lets themselves go. Professor Cox thinks this makes your throat open more and your vocal chords (the parts of the body responsible for all the noise we make) vibrate quicker.
We tested this out with a group of kids. We got them all to scream and used a sound level meter to find out how loud it was.
Their screams tended to be scarier on their second go, when they were warmed up. And we all agreed that the louder screams were the scariest.
Finally it was my turn to scream into the special microphone.
The machine that measures how loud the screams are
Now I think my screams sound rubbish. It's not like the ones you see in films or anything like that.
After three attempts I managed to record a scream measuring 117 decibels. That's pretty loud
but not as loud as the kids I met today.
Professor Cox wants to know more about screaming and has created a Scariest Screams website where you can vote for which screams you find the scariest. This will help him find out more about what makes some screams scarier than others."