hearing science exam 3

absolute threshold

lowest level of stimulation that is detectable

differential threshold

smallest magnitude of difference that allows a person to differentiate between two nearly identical stimuli

20 Hz to 20 kHz

frequency range most sensitive to humans

500-4000 Hz

Frequency range/ threshold for speech

100 dB SPL

the discomfort frequency level for speech

125-140 dB SPL

the pain frequency level for speech

Dynamic range of hearing

range between absolute threshold of audibility and threshold of discomfort and pain 0dB SPL - 140 dB SPL

Weber's Law

A stimulus must be increased by a certain proportion of itself to be perceived as a different sound

1 vs 20 or 50 vs 51

masking

when one sound interferes with the detectability of another sound

a tone close to original frequency

the most efficient masker of a tonal signal/ pure tone

psychophysical tuning curve (PTC)

curves plotted to reflect the effectiveness of maskers at different frequencies for one pure tone

azimuth in horizontal plane

direction of angular displacement of a sound source relative to listener

(plane parallel to the ground passing through the listeners head)

interaural time difference (ITD)

sound arrives at one ear before the other, depends on azimuth of sound source

Interaural level difference (ILD)

intensity level of sound is greater at one ear than the other (stimulus travels greater distance to reach further ear --> inverse square law)

minimal audible angle

smallest angular separation between two sounds detectable by a listener ( a higher ____ = poor discrimination [tends to be at higher frequencies])

lateralization

difficulty separating ITD and ILD variables to examine them separately in free field

ITDs

the most distinctive localization

simultaneous masking

when signal and masker occur at the same time

forward masking

when masker comes on off prior to occurrence of signal

backward masking

when masker comes on and off after occurrence of signal

Conductive hearing loss

when sound waves are unable to travel through outer or middle ear

Sensorineural hearing loss

occurs when there is damage to inner ear, cochlea, or auditory nerve

Mixed hearing loss

when there is an occurrence of sound waves being unable to travel through outer or middle ear and when there is damage to inner ear, cochlea, or auditory nerve

Site of lesion

specific location where damage or dysfunction is occurring

Unilateral hearing loss

Hearing loss in one ear

Bilateral hearing loss

Hearing loss in both ears

Characteristics of hearing loss

difficulty understanding speech, increased volume of tv or phone, difficulty in loud or noisy areas

10 - 15 dB

Normal hearing

16 - 25 dB

sight loss

26 - 40 dB

Mild hearing loss

41 - 55 dB

moderate hearing loss

50 - 70 dB

moderate to severe hearing loss

71 - 90 dB

severe hearing loss

91+ dB

profound hearing loss

air conduction

the process by which sound waves enter the ear through the pinna (air)

bone conduction

the conduction of sound to the inner ear through the bones of the skull

air bone gap

the difference, in decibels, between the air conduction threshold and the bone conduction threshold

audiogram

A graph that shows the result to a pure tone hearing test