Sound for Interaction class 5

Frequency and Pitch

adding sound waves

• Interference and Beats

http://www.school-for-champions.com/science/soundbeat.htm

Phase

Phase in measured in degrees.

The phase of a sound has to do with the time domain.

Adding two Simple Harmonic waves -Applet

Adding two Simple Harmonic waves2 - Applet

http://library.thinkquest.org/19537/java/Wave.html

In class demo of how waves add show beats

Timbre/Harmonic structure

Timbre is a descriptive word used to help describe the 'color' and envelope of a sound.

All sound is made up of simultaneous sounding tones. In the 1700 Joseph Fourier a French mathematical physicist proved that all sound can be synthesized be adding sine waves. The way these sine waves are added together make things sound different.

http://www.gac.edu/~huber/fourier/

Different sound don't sound the same due to different fundamental frequencies, harmonics, complexity, and envelope.

Timbre is made up of Harmonics and Envelope. The Harmonics define the different frequencies present in a a sound and the envelope defines the amplitude through time.

Harmonic Structure

http://www.rane.com/par-t.htm Harmonics defined @ rane

Understanding Harmonics Fundamental Frequency and Harmonics Instruments

   * Guitar string
   * Open-End Air Columns
   * Closed-End Air Columns

Natural harmonics are multiple of the fundamental/

Understanding Harmonics @ Harmony Central

http://ptolemy.eecs.berkeley.edu/~eal/eecs20/berkeley/scale/demo/timbre.html

http://www.umanitoba.ca/faculties/arts/linguistics/russell/138/sec4/source.htm

http://library.thinkquest.org/19537/cgi-bin/showharm.cgi

Home Work

Sound for Interaction Flash Piano