The Physics of SoundSound begins with a vibration of an objectVibrating object transfers energy to air mediumAll complex vibration patterns seen as a combination of many simple vibration patterns
Simple harmonic motionElastic restoring forceMove object from equilibrium point, force returns it to equilibrium pointForce is proportion to distance from equilibrium Displacement
Simple Harmonic MotionHarmonic oscillations, or sinusoid (sine) curves
Simple Harmonic Motion, contAmplitude: Maximum displacement from one extreme to resting positionPeriodic vibration: Wave repeats itselfFrequency (F): Number of cycles per sec (Hz)Period (T): Time (sec) to complete one cycleF = 1 / TPhase: Progression of wave through one cycle (measured in degrees)
Simple Harmonic Motion, contDecay of harmonic motion
Additivity and Superposition of Sine Waves
Additivity and Superposition of Sine Waves, cont
Fourier Decomposition or Fourier Analysis
Fourier Decomposition, contSystems for Naming Frequency ComponentsFreq.HarmonicsOvertonesPartials
f0FundamentalFundamental1st Partial2f0 2nd Harmonic1st Overtone2nd Partial3f0 3nd Harmonic2st Overtone3nd Partial4f0 4nd Harmonic3st Overtone4nd Partial
Fourier Decomposition, cont
The Perception of PitchThe physiology of the ear
The Perception of Pitch, contThe place theory of pitch perception
The basilar membrane as a set of independently tuned resonatorsTone of single frequency causes corresponding place on basilar membrane to vibrate
The Perception of Pitch, contThe frequency theory of pitch perception
Basilar membrane vibrates to match frequencyBecause of refractory period, nerve fibers cannot encode high frequencyVolley principle: nerve fibers working together can encode high frequencies
The Perception of Pitch, contThe psychophysics of frequency
The Mel Scale: Perceived pitch as a function of frequencyNon-linear relation between frequency and pitch
The Perception of Pitch, contThe Cognitive-Structural approach
Octave equivalenceTones in a 2:1 frequency ratio have a special relationEvidence for octave equivalence:The harmonic seriesThe musical pitch set
The Perception of Pitch, contThe Cognitive-Structural approach
Psychological evidence for octave equivalenceDeutsch (1973) Standard Intervening SequenceComparison
The Perception of Pitch, contThe Cognitive-Structural approach
Psychological evidence for octave equivalenceOctave-scramble nursery rhymes
The Perception of Pitch, contA bi-dimensional approach
Tone / Pitch Height: A continuous dimension that increases with frequencyTone / Pitch Chroma: Circular component representing tones with 2:1 freq. ratioThe pitch helix
The Perception of Pitch, contA bi-dimensional approach
Shepard / Circular tones
Single tones:
Continuous glide:
Tritone paradox:
The Perception of LoudnessThe psychophysics of loudness
Audibility curves
The Perception of Loudness, contThe psychological scale of loudness
Sones scale
The Perception of TimbreThe steady state component approach
Components that remain the same over timeProblems with the steady state view of timbre
The Perception of Timbre, contThe importance of transient components
Onset rapidity: Rate of onset of the toneNoise bursts: Amount/type of noise in beginning of toneSpectral energy shift: Changes in relative intensity of harmonics over time
The Perception of Timbre, contThe perceptual similarity of musical timbreJohn Greys studies of musical timbre
Top Related