Auditory system class notes Flashcards
What is the definition of sound?
pressure waves in the air produced by a vibrating object, that are then detected by the auditory system
What is the difference between a distal and proximal stimulus
Distal stimulus = an actual object that has vibrating sound, but is just an object alone
eg. tree, lamp, car
Proximal stimulus = the pattern of kinetic energy at the ear drum (the energy the distal stimulus produces that we perceive)
eg. when looking at a tree, the light reflecting off the tree that hits your eyes is the proximal stimulus, the tree itself is the distal stimulus
Explain the “phase” aspect of sound
The “phase” is the point along the wave (the stage of the wave we are at), which is measured in degrees
0 degrees, 90 degrees, 180 degrees, 270, 360, then starts again at 0
(you cany hear the phase of a wave)
Can you explain the Amplitude aspect of sound
The amplitude is the height of the wave (how intense it is)
What is the range of the amplitude for a sound wave?
threshold = lowest possinle sound an average human can hear is 0.0002 dynes/cm2
Maximun = 200 dynes (would be painful to hear)
What is Frequency?
The number of sound waves per second
What is frequency measured in?
Hertz (Hz) = #of cycles / time (s)
What is “Loundness?”
The perceptual experience of sound intensity (not volume)
To double loudness, you increase the dB by ___ dB
10 dB
so 60 dB is twice as loud as 50 dB (even though its 10 units more)
A _____ of loundess is a perceptual unit of loundess in your head
Sone
What is a “pitch”
The quality of a sound ranging from low to high (like a musical scale)
How is pitch effected by intensity
High frequency sounds seem higher pitched as intensity increases, and low frequency sounds seem lower pitched as intensity increases
Sound lower than 10ms long is heard as a _____
click
In a chromatic scale of musical notes, one note is an _______ above another when its frequency is ______ that of the comparison.
octave ; double
What is fourier analysis?
Breaking down a sound into its components
Explain the “fundamental” and “harmonics” in fourier analysis.
The fundamental is the lowest frequency in a fourier spectrum of a complex sound wave.
The ahrmonics are the multiples of the funamentalo
What is the “timbre” of a sound?
The character or nature of a sound. The uniqueness.
What makes a voilin sound different than a piano
