Unit 3 Flashcards
(87 cards)
Sound Can be defined As…
A phys stim OR a perc response
Sound as phys stim
Changes in air pressure/other medium
-Tree falling causes pressure change w/o or w/ someone’s presence to hear it, so it does make a sound
-Ex “lvl sound of 10dB”
Sound as Perc Reponse
Sound is exp while hearing
-Without anyone around to exp the sound of the tree falling, it doesn’t make one
-Ex, “a trumpet pierced the air!”
Sound as Pressure Change / Phys Stim
Movement/vibrations of objects causing pressure changes around said object
Condensation
THe process of pushing air molecules together, causing change in density of molecule
Sound wave
DEC density of air molecules/pressyre via rarefaction in alt H&L patter, impacting neighboring molecules
-~340meters/s, 1500m/s in water
Pure Tones
Simple sound waves, when pressure changes in air occur in pattern of sine wave
-Can be found in ENV
Amplitude
Size of pressure changes & frequency in sound
Frequency
The number of times/sec pressure changes repeat
Decibel - dB
Unit of sound, 1 dB = 20 X logarithm(p/po) (p = sound pressure of stim, Po = standard sound pressure)
Sound Pressure Lvl (SPL)
20 microspascals
-Multiplying pressure by 10 adds 20dB
-See notes for table
Frequency
of cycles per second causing repeating changes in pressure, the phys measure for perc of pitch
-Measured in Hz (1 cycle/s)
-Ex, a X5 repeat in one sec = 5-Hz
-Humans = 20Hz-20,000Hz
Periodic Tone
Waveform repeats as a property, creating a complex tone
-Consist of pure tones
-Built via additive synthesis
Fundamental Frequency
The rep rate of a complex tone
Additive Synthesis
of sine-waves components added together, creating a complex tone
-Beginning via pure tones
Harmonics
Additive tones, adding fundamentals (first harmonic) and higher harmonics = waveform of complex wave
Frequency Spectra
Indicates a complex tone’s fundamental frequency and harmonics w/out drawing waveform
Removing a harmonic…
Changes a tone’s waveform but repetition remains the same b/c fundamental frequency. Removal = space where waveform holds info indicating fundamental frequency.
Loudness
Quality movement related to amplitude / sound pressure / lvl of audio stim
Pitch
The perceptual quality describing H/L, attribute of audio sensation
-Similar to phys property of frequency
-L fundamental frequencies ass w/ L pitch, H w/ H
-Determined by harmonic spacing and repetition of waveform indicating fundamental frequency
Tone Height
Perc exp of INC pitch accompanies INC in tone fundamental frequency
-L at left end of piano (27.5Hz), INC up to the right end (2166Hz) (perc of INC in tone height)
-ABDCDEFG repeats going up tone height
Tone Chroma
Notes w/ same letter, going up/down an octave interval
-A1 fundamental frequency of 27.5Hz, A3 is 110Hz
Effect of the Missing Fundamental
Constancy of pitch, even w/ removal of fundamental or harmonics, leaving per of periodicity of pitch
Periodicity Pitch
Pitch percieves when fundamentals/other harmonics are removed
-# of consequences, ex speaking on the phone (phone can’t produce actual male pitch of below 300Hz, makes a similar sound)