pure-tone audiometry

what is pure-tone audiometry?

a hearing test that determines the softest intensity a person can hear at specific frequencies?

what does frequnecy measure?

pitch, measured in Hertz (Hz)

what does dB HL measure?

hearing level relative to a standardized audiometric reference

what does moving to the right on an audiogram mean?

frequency increases

what does moving down an audiogram mean?

the hearing threshold is poorer and the sound must be louder to be detected

what does the symbol O represent?

right-ear air conduction, usually red

what does the symbol X represent?

left-ear air conduction, usually blue

what is a hearing threshold?

the lowest intensity at which a person responds to sound in 50% of ascending trials

what is a suprathreshold?

a stimulus presented above the person’s hearing threshold

how do you calculate sensation level?

presentation level in dB HL minus the person’s threshold in dB HL

what is otoscopy?

examination of the external ear canal and tympanic membrane using an otoscope

why is a case history important?

it helps identify hearing concerns, symptoms, medical history, noise exposure, and other relevant background

what is the degree range of normal hearing?

-10 to 20 dB HL

what is the degree range for mild hearing loss?

21 to 40 dB HL

what is the degree range for moderate hearing loss?

41 - 60 dB HL

what is the degree range for moderately severe hearing loss?

61-70 dB HL

what is the degree range for severe hearing loss?

71 to 90 dB HL

what is the degree range for profound hearing loss?

91 to 120 dB HL

in what increments are thresholds recorded?

5 dB steps

what does a no-response symbol mean?

the person did not respond at the maximum intensity tested

a no-repsonse symbol mean it is __ an actual measured threshold

not

what frequencies are included in the PTA?

500, 1000, 2000 Hz

what is the PTA formula?

PTA= (T500​+T1000​+T2000​​)/3

why is PTA useful?

it provides an average of the three specified AC thresholds and helps cross-check reliability against speech hearing

what is symmetric hearing loss?

right and left ear AC threshold within 10 dB of each other

what is asymmetric hearing loss?

right and left ear AC threshold separated by 15 dB or more

what does air conduction test?

the overall hearing pathway through the outer, middle, and inner ear

what does bone conduction help assess?

inner-ear hearing sensitivity by transmitting vibrations through the skull

what is the usual frequency range for BC testing?

500-4000 Hz

why is masking used?

to help ensure that the response comes from the intended test ear rather than the non-test ear

to which ears does an unmasked BC threshold generally apply?

both ears

what

what is the general AC/BC pattern for conductive hearing loss?

AC thresholds are poorer than normal, while BC thresholds are normal

what is the general AC/BC pattern for sensorineural hearing loss

both AC and BC thresholds are poorer, without a significant air-bone gap

what is the general AC/BC pattern for mixed hearing loss?

both AC and BC thresholds are poorer, and AC is poorer than BC

which thresholds determine configuration?

air-conduction thresholds

what is a flat configuration?

thresholds are relatively similar across frequencies, usually within a 20 dB range

what is a sloping configuration?

thresholds become poorer as frequency increases

what is a precipitously sloping configuration?

thresholds decline by at least 25 dB across at least one octave

what is an octave?

doubling of a frequency

what is a rising/reverse-slope configuration?

thresholds improve as frequency increases, meaning hearing loss is greater in the low frequencies

what is cookie-bite configuration?

middle-frequency thresholds are poorer than the low and high frequency thresholds

what is a notch configuration?

a sharp decline at one frequency followed by improvement at an adjacent frequency

does normal hearing need a configuration label?

no, describe it as normal hearing