We talked about vibrations and what sound means. We also discussed making our own instruments and discovered that if we held two cans together and blew they would make a very cool noise. We looked at whoopie cushions and how they made noises, then we looked at a huge whoopie cushion and learned that it was the vibration or air particles that made the noise. We looked at a slinky and thought about how it can be used to demonstrate the movement of sound waves. Discussing how sound moves by squeezing and stretching through the air, we were also reminded of the fact that there is bit of sound in space but not enough for humans to hear it. We learned how cells inside the cochlea in the ear can become damaged when exposed to sound too much at loud concert or football match and discussed how this could be permeant with too much exposure. We were advised to keep sound through headphones on about half volume to avoid any damage. We learned that humans only hear from 20-20 thousand vibrations a second but elephants can recognise as low as 4 per second. Elephants 'hear' infrasonic vibrations (really slow ones) through their feet though. We also revised how vibrations are measured in hertz and looked at sound in a glass in which there was water. There was a rise in frequency because less water means faster vibrations and higher frequency waves.