So. Zak has just demonstrated to me that hot water coming from a kettle sounds very different (much deeper) to cold water coming out of a kettle... both going into the same container (in this case a mug). This came up after him going to make a brew and saying "the water is cold I can hear it" to which I replied "u wot m8 " He then got me to pour and I could easily tell the difference. Does anyone know of any other odd things like this and why does it happen?