Sound Study Guide What is sound?Pitch vs. Volume How we hear sound Click on your study guide choice! Videos from class
What is Sound? Sounds are vibrations Like in our investigations, this ruler shows how objects that make sound make vibrations. Air molecules vibrate and send these vibrations to your ear where you “hear” the sounds!
What is Sound? Sounds travel in waves Each “wave” represents a sound wave. Remember that the molecules vibrate and pass on the vibrations to the molecules around them to move the wave to your ear! http://odin.physastro.mnsu.edu/~eskridge/astr101/Surface_waves.jpg
Sound through materials Sounds pass through denser forms of matter better Click here to visit a site on sound and matter density!here
Review Questions If an object does NOT vibrate, will it make a sound? Yes No
Review Question What material does sound travel through the best? Solid Liquid Gas
Correct! Sounds travel through denser forms of matter like solids because the molecules are closer together and the vibrations get passed on faster!
Correct! Even if you cannot see the vibrations, anything that makes a sound HAS to vibrate! Great Job! Move onto the next study guide!
Pitch vs. Volume Pitch is how HIGH or LOW a sound is Listen to the differences from our nail pitch investigation! Listen
Pitch The FASTER the vibrations (higher frequency) … The HIGHER the pitch The SLOWER the vibrations (lower frequency)… The LOWER the pitch Pitch is the speed of vibrations High Frequency/ pitch Low Frequency/ pitch http://www.sciencenewsforkids.org/articles/20081015/Feature1.asp
Changing Pitch Think back to our pitch investigations… Changing the length of a ruler Changing the length of the string Changing the length of the slide whistle What does changing length do to pitch? The shorter the length, the higher the pitch The longer the length, the lower the pitch!
Tension Like the string board, changing the TENSION in a string will change the pitch. INCREASING the tension (making it tighter) will INCREASE the pitch. DECREASING the tension (making it looser) will DECREASE the pitch.
Think Back… What was ONE way we changed pitch in our investigations? Shorten the string or column of air Hit the drum with more force Add more strings of the same length
Correct! To make the pitch HIGHER…SHORTEN the string or instrument! To make the pitch LOWER…LENGTHEN the string or instrument! Next Question!
Our Ears! Our ears are made to collect sound vibrations and convert them into electric signals that are sent to the brain! Vibrations http://www.kids-ent.com/images/clinical
Anatomy of the Ear Take a close look. Do you remember the process of hearing?
How we hear sound 1. Vibrations enter the outer ear 2. Vibrations cause the eardrum to vibrate 3. The vibrating eardrum makes the three middle ear bones vibrate 4. The inner ear bones causes the fluid in the cochlea to vibrate 5. The cochlea fluid makes little hairs move which create nerve signals that is understood as sound in your brain!
Kidshealth.org Read this article and watch this video on how your ear works. Did you find out anything new? Kidshealth.org Animation of how your ear works
Review Question What process is NOT part of the hearing process? Vibrations are collected by the outer ear The Eardrum causes the middle ear bones to vibrate The cochlea stops the sound before it reaches the brain
Correct! The cochlea does not stop the sound. It actually converts the sound to nerve signals which allow you to HEAR the sound! Let’s move on
Ear Damage Can a loud sound hurt our ears? YES! Loud sounds can damage some inner parts of the ear. This can lead to temporary or permanent hearing loss! Protect your hearing by moving away from the sound or by wearing ear protection.
Ear Damage Some people are born with hearing defects or get them from situations such as accidents. While there are a variety of reasons why somebody can lose their hearing, many defects are from a mechanical part of the ear that does not work properly (example, a burst eardrum cannot pass on vibrations!).
Ear Damage There are ways to help people who have hearing defects. One example is a hearing aid which helps make sounds louder for the user. It is worn in or around the ear.
Ear Damage For some people who cannot hear sounds, sign language is a type of communication that uses hand movements to indicate letters, words, and sentences. www.asluniversity.com/.../fingerspelling.htm
Review Question True or False? Loud music can cause hearing loss. True False
Correct! Protect your hearing by moving yourself away from loud sounds or by using ear protectors! Let’s move on