Week 6 Flashcards
W = V / F
What is the formula for wavelength in sound conduction?
Wavelength = velocity / frequency
Genereally expressed as a R…
How is sound amplitude generally expressed?
Sound amplitude is generally expressed as a ratio, with the standard being the mean hearing threshold
In relation to frequency and amplitude
What is the range of human hearing in terms of frequency and amplitude?
Frequency = 20 - 20,000 Hz
Amplitude = 0-140dB
A related H-L
What is presbycusis?
Age related hearing loss
OE = A, ME = A, IE = F
What are the three parts of the ear and their mediums?
Outer ear (air), middle ear (air), inner ear (fluid)
Acts as a L, converts H A/L F to L A/ H F, Imp match
What is the role of the ossicles in the middle ear?
Act as a lever, convert high amplitude/low force, motion at the eardrum, into low amplitude/high force motion at the oval window, aids impedence matching
Involves 2 M that pulls St away from OW in response to L S
What is the stapedius reflex?
The stapedius reflex involves two muscles that pull the stapes away from the oval window in response to very loud sounds, decreasing transmission of vibrational energy to the cochlea and preventing hearing damage
Sc V, Sc M, Sc Ty
What are the three scalae of the cochlea?
Scala vestibuli, scala media, and scala tympani
O H cells act as M to A sound, I H cells are Re for Se
What is the function of the outer and inner hair cells in the cochlea?
Outer hair cells act as motors (prestin) to amplify sound, while inner hair cells are responsible for sensation
Different F of S cause different L of Bas Mem to Vib
What is the pitch place theory?
The pitch place theory, proposed by Georg von Békésy, states that different frequencies of sound cause different locations on the basilar membrane to vibrate
Dec of any WF into Sin W of various F, which the ear performs to An S
What is Fourier analysis in the context of hearing?
Fourier analysis is the decomposition of any waveform into sine waves of various frequencies, which the ear performs to analyze sound
Ech in response to C D to the ear, used to A hearing in NB and can IE P
What is the role of otoacoustic emissions?
Otoacoustic emissions are echoes in response to clicks delivered to the ear, used to assess hearing in newborns and can indicate inner ear problems
ILD = Vol D between ears, better for H F, ITD = Ti D between ears
What are inter-aural level differences (ILD) and inter-aural time differences (ITD)?
ILD refers to volume differences between ears, better for high frequencies. ITD refers to timing differences between ears, better for low frequencies
Ability to U C from an I S among others, involving So Lo Cu and Vi
What is the ‘cocktail party’ effect?
The ability to understand conversation from an individual speaking among many others, involving sound localization cues and vision
Judgement of Dis & Dir
What factors influence sound localization?
Judging distance (high frequencies travel less well, expectation, relative attenuation, echoes) and judging direction (inter-aural timing/phase differences, inter-aural volume differences, spectral coloring by head and pinna).
