Lesson 1 - Posted on 2013-03-21 by Griffin Plack

This Lesson introduces the basic principles of Sound and Hearing. It begins by foucsing on how sound travels to the ear. Sound travels through the use of medium. It does this by causing the medium to vibrate, the vibration causes the air particles from the medium (be it vocal chords, wood, strings, etc.) to be displaced which eventually causes those particles to reach the tiny hairs inside the human ear which then send electrical impulses to the brain notifying the brain that it is hearing a particular sound. Next, Waveforms are discussed. A waveform is the graphical representation of the amplitude of a signal versus time at a given instant. There is much math involved with representing a waveform. Velocity is the measurement of how fast sound travels thorugh a medium compared to the density of the medium. The Pitch of a sound is its frequency measured in Hertz (Hz). If the frequnecy of the sound is above 20,000 Hz it is reffered to as ultrasonic. Conversely, a frequency below 20 Hz is reffered to as infrasonic. Sound Intensity is something humans can percieve as loudness. 0 Hz is where our Threshold of hearing begins and 125 Hz is where our Threshold of Pain begins. Binaural localization is the ability to use both ears to determine the source of a sound.