ILE STUDY GUIDE 2026 PRACTICE MATERIAL
SOLVED ITEMS EXPERT REVIEWED
◉ What does increasing the compression ratio do, and when would you
use this? Answer: Soft sound gain is unaltered, but gain for
moderate/loud sounds is lowered. Most often used if a PT complains
loud/moderate sounds are too loud or background noise is too loud. **
sometimes you use this on just certain frequencies, for example, high
frequencies if they complain dishes are too loud, or low frequencies if
they complain their voice is echo-y
◉ What happens when you raise a knee point, and when would you do
this? Answer: You will decrease gain for soft sounds and raise gain for
moderate/loud sounds. Most often used if they hear soft sounds better
than moderate ones ( like hearing the table across from them better than
their own in a restaurant) or when they complain about hearing a HA's
circuit noise.
◉ What does lowering the kneepoint do, and when would you do this?
Answer: Lowering the KP will lower gain for moderate and loud sounds,
and increase gain for soft sounds below the original KP. Mostly used
when a PT complains they can't hear soft sounds like soft voices, bird
chirping, or ticking clocks.
◉ What are the two types of compression? Answer: Input compression -
when the input level of a HA determines when compression is activated.
,Output compression - when the output (input + gain) of the HA
determines when compression is activated.
◉ What is Wide Dynamic Range Compression? Answer: (WDRC) This
is what most HA's utilize today, and allows the signal to be packaged
withing a user's DR. Typically WDRC HA's have low (35-55 dB SPL)
KPs and low (1:1 - 1:4) ratios
◉ What is the Compression Ratio? Answer: The ratio of change between
the input and output of a HA. This determines how much compression
will occur.
◉ What is the Kneepoint? (KP) Answer: The lowest level at which
compression is applied
◉ What is Harmonic Distortion? Answer: Harmonic distortion occurs
when a single frequency is presented to the input of a hearing aid and the
output contains the original frequency plus additional undesired
frequencies that are harmonically related to the original frequency.
ANSI uses a harmonic distortion test that measures the distortion rate at
specific Hz.
◉ Frequency Response Curve Answer: Used in ANSI testing. A gain
curve is run with the input sound at 60 dB SPL to simulate conversation
level. You get the frequency range calculation from this test.
,◉ Reference Test Gain (RTG) Answer: Used in ANSI testing. Input
sound is set at 60 dB SPL to simulate conversation level; and then the
HFA gain is adjusted to HFA-OSPL90 -77 dB. The answer is the RTG.
◉ Full On Gain (FOG)? Answer: Used in ANSI testing. The HFA-FOG
is measured and recorded w/ the input set at 50 dB SPL
◉ Maximum Output Curve ( OSPL90) Answer: Used in ANSI testing.
It's the max output of a HA. Input is set to 90 dB SPL to test. Notes the
max at each tested frequency. HFA is noted from this test.
◉ What must be done to an aid before ANSI testing? Answer: 1-
Occlude all vents on outside of aid
2- Set to test mode with gain full on, output at max, and bandwidth to
max
3-Telecoil should be turned off and only turned back on when testing
SPLITS
◉ What couplers do do you use with what instruments when ANSI
testing? Answer: HA-1 = ITE
SB-1 = RIC and thin tube BTE's
HA-2 = BTE
, ◉ What is a coupler? Answer: A joiner for a HA that is designed off the
vol of an average ear (2cc). Used to connect the HA to a testing box for
ANSI tests.
◉ What is Adaptive Feedback Supression? Answer: This allows a HA to
detect and minimize feedback on it's own.
** There is also static feedback supression.
◉ What is Digital Noise Reduction (DNR)? Answer: This is an
algorithm which allows a HA to seperate desired signals ( like speech)
from undesired ones ( like noise)
◉ What are Multiple Memories? Answer: A HA feature that allows
saved programes to optimize preformance is multiple enviorments, like
the car, church, ect.
◉ What are Directional Microphones? Answer: Directional Mics are
mics facing multiple directions in a HA. This allows better signal to
noise ratio gain as sound to the front of the PT is louder than that
towards the rear. They can be adaptive, fixed, automatic, or manual.
◉ What are the most common HA battery sizes? Answer: 675 - used for
Power BTE's and cochlear implants
13 - Smaller BTE's and ITE's
SOLVED ITEMS EXPERT REVIEWED
◉ What does increasing the compression ratio do, and when would you
use this? Answer: Soft sound gain is unaltered, but gain for
moderate/loud sounds is lowered. Most often used if a PT complains
loud/moderate sounds are too loud or background noise is too loud. **
sometimes you use this on just certain frequencies, for example, high
frequencies if they complain dishes are too loud, or low frequencies if
they complain their voice is echo-y
◉ What happens when you raise a knee point, and when would you do
this? Answer: You will decrease gain for soft sounds and raise gain for
moderate/loud sounds. Most often used if they hear soft sounds better
than moderate ones ( like hearing the table across from them better than
their own in a restaurant) or when they complain about hearing a HA's
circuit noise.
◉ What does lowering the kneepoint do, and when would you do this?
Answer: Lowering the KP will lower gain for moderate and loud sounds,
and increase gain for soft sounds below the original KP. Mostly used
when a PT complains they can't hear soft sounds like soft voices, bird
chirping, or ticking clocks.
◉ What are the two types of compression? Answer: Input compression -
when the input level of a HA determines when compression is activated.
,Output compression - when the output (input + gain) of the HA
determines when compression is activated.
◉ What is Wide Dynamic Range Compression? Answer: (WDRC) This
is what most HA's utilize today, and allows the signal to be packaged
withing a user's DR. Typically WDRC HA's have low (35-55 dB SPL)
KPs and low (1:1 - 1:4) ratios
◉ What is the Compression Ratio? Answer: The ratio of change between
the input and output of a HA. This determines how much compression
will occur.
◉ What is the Kneepoint? (KP) Answer: The lowest level at which
compression is applied
◉ What is Harmonic Distortion? Answer: Harmonic distortion occurs
when a single frequency is presented to the input of a hearing aid and the
output contains the original frequency plus additional undesired
frequencies that are harmonically related to the original frequency.
ANSI uses a harmonic distortion test that measures the distortion rate at
specific Hz.
◉ Frequency Response Curve Answer: Used in ANSI testing. A gain
curve is run with the input sound at 60 dB SPL to simulate conversation
level. You get the frequency range calculation from this test.
,◉ Reference Test Gain (RTG) Answer: Used in ANSI testing. Input
sound is set at 60 dB SPL to simulate conversation level; and then the
HFA gain is adjusted to HFA-OSPL90 -77 dB. The answer is the RTG.
◉ Full On Gain (FOG)? Answer: Used in ANSI testing. The HFA-FOG
is measured and recorded w/ the input set at 50 dB SPL
◉ Maximum Output Curve ( OSPL90) Answer: Used in ANSI testing.
It's the max output of a HA. Input is set to 90 dB SPL to test. Notes the
max at each tested frequency. HFA is noted from this test.
◉ What must be done to an aid before ANSI testing? Answer: 1-
Occlude all vents on outside of aid
2- Set to test mode with gain full on, output at max, and bandwidth to
max
3-Telecoil should be turned off and only turned back on when testing
SPLITS
◉ What couplers do do you use with what instruments when ANSI
testing? Answer: HA-1 = ITE
SB-1 = RIC and thin tube BTE's
HA-2 = BTE
, ◉ What is a coupler? Answer: A joiner for a HA that is designed off the
vol of an average ear (2cc). Used to connect the HA to a testing box for
ANSI tests.
◉ What is Adaptive Feedback Supression? Answer: This allows a HA to
detect and minimize feedback on it's own.
** There is also static feedback supression.
◉ What is Digital Noise Reduction (DNR)? Answer: This is an
algorithm which allows a HA to seperate desired signals ( like speech)
from undesired ones ( like noise)
◉ What are Multiple Memories? Answer: A HA feature that allows
saved programes to optimize preformance is multiple enviorments, like
the car, church, ect.
◉ What are Directional Microphones? Answer: Directional Mics are
mics facing multiple directions in a HA. This allows better signal to
noise ratio gain as sound to the front of the PT is louder than that
towards the rear. They can be adaptive, fixed, automatic, or manual.
◉ What are the most common HA battery sizes? Answer: 675 - used for
Power BTE's and cochlear implants
13 - Smaller BTE's and ITE's
