1. SOUND WAVES & BEAT FREQUENCY

2. SOUND WAVES Sound waves are caused by vibrations Vibrations cause contraction and expansion of an object, which creates regions of high and low pressure in the air (or medium that sound is traveling through) High pressure regions are called COMPRESSIONS Low pressure regions are called RAREFACTIONS

3. SOUND WAVES Sound waves are longitudinal The vibrations of particles in a sound wave move parallel to the direction of the wave We only hear sound waves because our ear drums interact with them

4. SOUND WAVES Sound travels at a constant speed through different mediums The speed of sound in air (at STP) is 343 m/s High pitch= high frequency= short wavelength Low pitch= low frequency= long wavelength Wave amplitude is associated with energy Higher amplitude = more energy In sound waves, a higher amplitude means a louder sound

5. BEAT FREQUENCY When two sound waves of similar frequency interfere with each other, they create beats of high and low volume The beat frequency is simply the difference between the frequencies of the two sound waves