Chapter 11-Introduction to the auditory system Flashcards
What is the physical aspect of sound?
Pressure changes in the air- or other physical mediums
What is the perceptual aspect of sound?
The experience of hearing
If a tree falls in the woods and no one is around to hear it; is there a sound according to the physical aspect
Yes there’s a sound bc here was a change in air pressure
If a tree falls in the woods and no one is around to hear it; is there a sound according to the perceptual aspect?
No there was not a sound because nobody was around to experience the tree falling
What is condensation?
AKA compressed
When a force pushes surrounding air molecules together causing a slight increase in air molecule density around the origin of the force leading to an increase of air pressure above atmospheric pressure
Do air molecules move during condensation and refraction?
Not a lot- similar to if a small boat floating in a puddle is interrupted by a pebble falling, the boat will bob up and down
What is rarefaction?
when there is a decrease in density of air molecules following condensation, resulting in lower air pressure
What does a cycle of rarefaction and condensation cause?
a soundwave
What kind of soundwaves are pure tones?
Sine waves
What is a frequency?
The amount of cycles per second that pressure changes repeat
What pitch does a higher frequency usually have?
Usually a higher pitch
What is the frequency of a pure tone/sine wave?
1/t (Hz)
What is amplitude?
The difference of the pressure change between the high and low peaks of a sound wave
What is the result of a larger amplitude
A louder sound
What represents a pitch change
darkening–> increased pressure
Lightening–> decrease in pressure
How is amplitude measured?
decibels–> this is a physical measurement
What range of Db can humans tolerate
0dB (barely audible) 160dB- pain threshold (jet plane taking off)
What is the connection between dB, loudness and amplitude
Amplitude is the change between the highest and lowest points of a wave. The larger the change in amplitude, the louder the sound. Loudness is dependent on the frequency of the wave and the dB This sound is measured in dB.
Can pure tones vary in frequency?
yes
How are frequency and pitch connected?
The frequency of a sound is linked to the perception of pitch. So a high frequency is equal to a high pitch.
What is a key difference between frequency and pitch?
Frequency is physical and can be measured. Whereas pitch is perceptual and cannot be measured- therefore it is very subjective
Define tone height
a perceptual experience of increasing pitch as sound frequency increases.
How we perceive pitch
this is the basis of the music industry
What is an example of tone height?
Keyboards have repeating notes A-G. These notes that are repeated but sound different are an octave apart and have the same tone chroma