take a look at this lion is it missing something it's strange to see a lion roar and not hear any sound isn't it let's try it again oops that wasn't right there that's more like it sound is important to our daily lives it's a major part of how we understand what's going on in our world but what is sound well sound is a movement of energy through matter sound occurs when a force causes matter to vibrate an example of this is plucking the string on a guitar when you pluck the guitar string it vibrates the
vibration of the string moves through matter and produces a sound they need to it's not as easy to see as the guitar string vibrations but parts of our threads vibrate when we talk put your hand on your throat and try it yourself doremi faso Lotito sound travels in what we call sound waves sound waves move from the source of the sound to our ears sound takes time to reach our ears but not too much time if you're close to the source of the sound in air sound moves at around 350 meters per second that's longer
than three soccer fields in only one second clap your hands you hear the sound almost as soon as your hands meet sometimes you will see something before you hear such as a jet flying across the sky this is because light travels much faster than sound sound waves can also bounce off walls in big empty spaces this makes an echo let's take a deeper look at a sound wave the frequency of a sound wave is the number of vibrations it makes in one second the frequency of a sound wave determines its pitch or how high or
low the sound is sound waves caused by faster vibrations have higher frequencies and makes higher pitched sound like birds chirping sound waves caused by slower vibrations have lower frequencies and make lower pitched sounds like a foghorn volume is how loud or soft a sound seems to your ears volume is determined by the amount of energy a sound has for example a sound like thunder has more energy and sounds louder to your ears the sound of typing has less energy and sounds softer fast vibrations with more energy will produce a high loud sound and slow vibrations
with less energy will produce a low soft sound what about slow vibrations with lots of energy what sort of sound do you think they will produce that's right they will produce a low loud sound to demonstrate just how important sound can be to our lives let's play a game can you guess where we are by listening to the sound did you guess it we're at the beach sound can give you hints about what's happening around you even if you can't see let's look at the same example in a different way here's a video of the
beach without sound now let's have our video editor Brian add in the sound of the waves crashing then the sea guns then the children playing in the sand and it all comes together to make this happen on video Brian carefully added the sound into the video at the right vulner video and film editors like Brian can also change the way things sound they can take the pitch of my voice another fire my hair out I'm feeling very warm I'm sleeping so the next time you listen to music explore the outdoors or even have a conversation
with someone think about the matter vibrating around you what are some of the sounds you hear around you right now [Music]
