<p>Name ______Period _____ Notes: Sound</p><p>Sound is a wave created by ______and propagated through a ______from one location to another. </p><p>Sound is a ______wave. The sound wave is transported from one location to another by means of particle-to-particle interaction. If the sound wave is moving through air, then as one air particle is displaced from its ______position, it exerts a push or pull on its nearest neighbors, causing them to be displaced from their equilibrium position. Since a sound wave is a disturbance that is transported through a ______via the mechanism of particle-to-particle interaction, a sound wave is characterized as a ______wave.</p><p>When a tuning fork vibrates, it creates areas of high pressure (______) and low pressure (______). As the tines of the fork vibrate back and forth, they push on neighboring ______. The forward motion of a tine pushes air molecules horizontally to the ______and the backward retraction of the tine creates a low-pressure area allowing the air particles to move back to the ______.</p><p>Frequency The ______object that creates sound could be the vocal cords of a person, the vibrating string of a guitar or violin, the vibrating tines of a tuning fork, or the vibrating diaphragm of a radio speaker. As a sound wave moves through a medium, each particle of the medium vibrates at the same ______. This makes sense (right? _____) since each particle vibrates due to the motion of its nearest ______. And of course the frequency at which each particle vibrates is the ______as the frequency of the original source of the sound wave.</p><p>• We hear frequencies of sound as having different ______. • A low frequency sound has a ______pitch, like the rumble of a big truck. • A high-frequency sound has a ______pitch, like a whistle or siren. • In speech, women have ______fundamental frequencies than men.</p><p>• The human ear is capable of detecting sound waves with a wide range of frequencies, ranging between approximately ______Hz to ______Hz. • Any sound with a frequency below the audible range of hearing (i.e., less than 20 Hz) is known as an ______. • Any sound with a frequency above the audible range of hearing (i.e., more than 20 000 Hz) is known as an ______.</p><p>Ultrasound Ultrasound is a medical imaging technique that uses ______sound waves and their echoes. The technique is similar to the echolocation used by bats, whales and dolphins. Name ______Period _____ Dogs can detect frequencies as low as approximately 50 Hz and as high as ______Hz. Cats can detect frequencies as low as approximately 45 Hz and as high as ______Hz.</p><p>Certain sound waves when played (and heard) simultaneously will produce a particularly pleasant sensation when heard. Such sound waves form the basis of ______in music. For example, any two sounds whose frequencies make a 2:1 ratio are said to be separated by an ______and result in a particularly pleasing sensation when heard. That is, two sound waves sound good when played together if one sound has ______the frequency of the other. </p><p>Loudness</p><p>Intensity: the rate at which a wave’s ______flows through an area Sound intensity depends on:  ______ ______Measured in decibels (dB)</p><p>Loudness is ______(This means it depends on the person who is hearing it.) Loudness is a ______, physical response to the intensity of sound. As intensity increases, so does ______, but loudness also depends on the listener’s ears and brain.</p><p>Intensity is caused by the ______of the vibration. Example: A vibrating guitar string forces surrounding air molecules to be ______and expanded. The ______that is carried by the wave is imparted to the medium by the vibrating string. The ______that is transferred to the medium is dependent on the ______of vibrations of the guitar string. If ______is put into the plucking of the string, then the string vibrates with a greater ______. The greater amplitude of vibration of the guitar string thus imparts more energy to the medium, causing air particles to be displaced a greater distance from their rest position. </p><p>The Decibel Scale: The decibel (abbreviated dB) is the unit used to measure the ______of a sound. The decibel scale is a little odd because the ______is incredibly sensitive. Your ears can hear everything from your fingertip brushing lightly over your skin to a loud ______In terms of power, the sound of the jet engine is about ______times more powerful than the smallest audible sound. That's a big difference!</p><p>On the decibel scale, the smallest audible sound (near total silence) is _____ dB. A sound 10 times more powerful is _____ dB. A sound 100 times more powerful than near total silence is _____ dB. A sound 1,000 times more powerful than near total silence is _____ dB. Name ______Period _____</p>