timbre (pronounced like: tamber) pure tones are very rare a single note on a musical instrument is a...
Post on 19-Dec-2015
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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”
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
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”)
Musical Intervals
• in music, notes are played together or in quick succession
• pairs of notes share a relationship called an interval
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
Musical Intervals
• f1= 400 f2 = 800
– (f2 = 2 x f1)…octave
• f1= 400 f2 = 600
– (f2 = 3/2 x f1)…perfect 5th
• f1= 500 f2 = 800
– (f2 = 8/5 x f1)…minor 6th
• f1= 400 f2 = 550
– (f2 = 11/8 x f1)
octave
perfect 5th
minor 6th
not quite a perfect fourth?!
Consonance and Dissonance
• Consonance is the degree to which two tones played together sound “good”
• Dissonance is the opposite
Consonance and Disonance
• Consonance seems to decrease with increasing complexity of the ratio of the tones
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
major minor
3 notes/3 intervals
4 notes/6 intervals (dominant 7)
4 notes/6 intervals (major 7)
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?
Auditory Scene Analysis
• Solving this problem is called Auditory Scene Analysis
• One important principle is proximity –in pitch, time, or spatial location
Auditory Scene Analysis
• Effect of timing proximity:Slow Fast
Auditory Scene Analysis
• Effect of timing proximity:
Pitc
h Do you hear this?
Pitc
h
Or this?
Slow Fast
Auditory Scene Analysis
• Effect of pitch proximity:closefar
Auditory Scene Analysis
• Effect of pitch proximity:
Pitc
h
Do you hear this?
Pitc
h
Or this?
closefar
Auditory Scene Analysis
• Effect of proximity:– auditory system groups together events
that happen close together in time and frequency