2. What are harmonics? Superposition of two (or more) frequencies yields a complex wave with a fundamental frequency

3. The Missing Fundamental Your brain so likes to track the fundamental of a set of harmonics that it will perceptually fill it in even when it is absent missing fundamental

4. Timbre (pronounced like: Tamber) pure tones are very rare a single note on a musical instrument is a superposition (i.e. several things one on top of the other) of many related frequencies called harmonics Pronounciation of “timbre”

5. Timbre the characteristic of a particular set of harmonics is called timbre –e.g. the set of harmonics generated when a particular key is pressed on a piano timbre is why we can tell the difference between the same notes played on difference instruments

6. Timbre Although any musical “note” is a superposition of harmonics, you still hear it as a single pitch (you hear its tone height) The pitch that you hear is (usually) the fundamental frequency (except in the artificial case of the “missing fundamental”)

7. Musical Intervals in music, notes are played together or in quick succession pairs of notes share a relationship called an interval

8. Musical Intervals Within each pair, the higher pitch (f2) is some multiple of the lower pitch (f1): –e.g. 200 hz and 400 hz -- f2 is two times f1

9. Musical Intervals f 1 = 400 f 2 = 800 – (f 2 = 2 x f 1 )…octave f 1 = 400 f 2 = 600 –(f 2 = 3/2 x f 1 )…perfect 5th f 1 = 500 f 2 = 800 –(f 2 = 8/5 x f 1 )…minor 6th f 1 = 400 f 2 = 550 –(f 2 = 11/8 x f 1 ) octave perfect 5th minor 6th not quite a perfect fourth?!

10. Consonance and Dissonance Consonance is the degree to which two tones played together sound “good” Dissonance is the opposite

11. Consonance and Disonance Consonance seems to decrease with increasing complexity of the ratio of the tones

12. Music is combinations of intervals played in series (with some rhythm) Combination of three different intervals is a chord (major or minor) Additional intervals modify the sound of the chord majorminor 3 notes/3 intervals 4 notes/6 intervals (dominant 7) 4 notes/6 intervals (major 7)

13. Auditory Scene Analysis Sounds don’t happen in isolation, they happen in streams of changing frequencies How does the system group related auditory events into streams and keep different streams separate?

14. Auditory Scene Analysis Solving this problem is called Auditory Scene Analysis One important principle is proximity –in pitch, time, or spatial location

15. Auditory Scene Analysis Effect of proximity: Pitch Do you hear this? Pitch Or this? SlowFast

16. Auditory Scene Analysis Effect of proximity: Pitch Do you hear this? Pitch Or this? closefar

17. Auditory Scene Analysis Effect of proximity: –auditory system groups together events that happen close together in time and frequency