The ear and sound Flashcards
chapter 10
physical definition of sound
pressure change
- mechanical waves
sound in water vs air
- it travels faster in water (1500ms)
water = 340 m/s
what are the physical properties of sound
- Amplitude
- frequency
- timbre
Amplitude
- relates to the loudness
- measured in decibels
Frequency
- relates to pitch
- defined as the number of times per second that a pattern of pressure repeats (Hz)
Audibility curve
created by the fact that lower frequency sounds need higher amplitudes to be hear at the same rate as higher frequency sounds
frequency range of humans
20 Hz to 16 000 Hz
decibel
tells us how loud something is compared to the quietist sound we can hear
- each increase refers to a big jump in intensity
- logarithmic
what does it mean that decibels are logarithmic
- relatively small changes in decibels can have large physical changes
- a increase in 10 db is x10 louder and an increase by 20db is x100
waveform
describes the shape of the sound wave
- can be simple or complex
Timbre
- difference in quality of sound that is not frequency or pitch
- change in quality of sound
complex waves
sound waves are made up of different combinations of simple waves
fourier analysis
represents complex wave form as a breakdown/sum of multiple pure sine waves
harmonic spectrum
the waves that sound is made up of including the fundemental frequency and the rest of the overtones
fundamental frequency
the lowest/dominant frequency component of a complex periodic sound
what are the 3 sections of the ear
- outer ear
- middle ear
- inner ear
parts of the outer ear
- pinna
- auditory canal
- tympanic membrane
pinna
funnels sound pressure waves into the canal and helps with localization of sound
auditory canal
tube that goes through the skull to the eardrum which carry the sound
tympanic membrane
- eardrum
- think sheet of skin at the end of the canal which vibrates to the middle ear
function of the middle ear
amplification and transmission
bones of the middle ear
- malleus/hammer
- incus/anvil
- stapes/stirrup
malleus
- hammer
- transmits vibration from tympanic membrane to incus