Midterm 2

Question 1

REUR/G

Answer 1

real ear absolute response/gain
Ex. REUR 53- input of 50= REUG of 3
*Measures the natural amplification created by the shape of the pinna and OPEN ear canal
REUR: REAL EAR UNAIDED RESPONSE–> The measurement of the absolute SPL level of an OPEN ear canal resonance, across all frequencies at the TM (input+gain+resonance=output)
REUG: REAL EAR UNAIDED GAIN–> the measurement of the gain added by the pinna shape and head diffraction effects and ear canal as measured in an open ear canal

Question 2

REOR/G

Answer 2

Real ear OCCLUDED Measurement of INSERTION LOSS *attenuation occurs with the hearing aid in place and turned off
REOR: a measurement of the attenuation of an input signal, across all frequencies, when a hearing aid is inserted and turned off
REOG: A measurement of the difference in input & output SPL (gain reduction), across frequencies, when the hearing
aid is inserted and turned off

Question 3

REAR/G

Answer 3

Real ear aided response: the frequency response and absolute aided output of an ACTIVATED hearing aid *changes based on depth of the coupler placement

Question 4

REIG

Answer 4

Real ear insertion gain Measures the amount of GAIN needed to overcome the insertion loss (REOR) and restore audibility of the signal *The difference between the AIDED response (REAR) and the UNAIDED response (REUR) of the ear canal REAR-REUR=REIG

Question 5

Why do we measure RECD?

Answer 5

1. Accurate audiometric conversion of a threshold measured in dB HL using inserts to dB SPL values
2. RECD creates personalized conversion factors for precise HL to SPL audiometric conversion

Question 6

RECD

Answer 6

Real ear to coupler difference The difference between the SPL resonance of a 2cc coupler and the SPL resonance of the real ear *the pink and green lines, shouldn’t have a huge gap

Question 7

If the acronym ends in R…

Answer 7

RESPONSE, represents an absolute measure of the SPL output arrive at the TM

Question 8

If the acronym ends in G…

Answer 8

GAIN, represents the difference between the output intensity and the input intensity Output-Input=Gain

Question 9

Why do we do REUR?

Answer 9

improves accuracy of prescriptive fitting by knowing an individual’s ear canal resonance It changes by ear canal differences:

• size, texture, shape, or presence of abnormal anatomy
• age: pediatric, adult, elderly
• one person can have 2 different REURSs

Question 10

Estimate of insertion loss based on vent size

Answer 10

0mm: completely occluded ear mold, no vent, getting occlusion and attenuation in low frequencies, attenuation gets stronger and insertion loss gets larger in high frequencies
large vent: release low frequency energy and attenuate high frequencies

Question 11

Why do we do REOR?

Answer 11

*won’t know if there is a slit leak unless you test this
1. to identify which low frequencies will be released through the vent *any gain you try to add in the frequency range of the vent effect will not increase the output, it will get released through the vent
2. To determine if the vent introduced
undesired standing wave effects that
would impact amplification
characteristics

Question 12

Why do we do REAR?

Answer 12

To view device’s absolute output in a unique ear canal DSL prescriptive target specifies REAR (OUTPUT) targets for signals arriving to the TM *DSL is commonly used in pediatrics, good for non-average ears *NAL is commonly used in adults

Question 13

Why do we do REIG?

Answer 13

We adjust GAIN for soft, moderate, and loud input signals within the programming software to achieve REIG NAL prescriptive targets specifies REIG (GAIN) targets to ensure loudness equalization is maintained

Question 14

REAR 85/90

Answer 14

Real ear aided response/MPO *use either 85 or 90 dB signal, 85 if it’s directly on patient’s ear or 90 in test box measures intensity of the output signal (MPO) arriving at the TM, when the input signal is sufficiently intense to drive the device to its maximum power output level

Question 15

How does an SPL-ogram differ from an audiogram. Why will measurement of the RECD improve the accuracy of the conversion?

Answer 15

The SPL-ogram converts the thresholds to an ascending loudness representation of loudness. The RECD can be a more accurate representation of the hearing condition and the treatment needed than an HL audiogram ever could. The dotted line at the bottom of the SPL audiogram grid represents the
average minimum audible sound pressure level. * show frequency specific LDL’s

Question 16

What is the measured SpeechMap REAR representing? Be prepared to describe the speech spectrum envelope and LTASS factors that are visible in the REAR.

Answer 16

REAR shows the degree of aided audibility achieved.
The green shaded area is a REAR using a 65 dB SPL input signal. The difference between the gray shaded area and the green shaded area represents the measured change in output between the unaided and aided conditions.

LTASS Speech Envelope: Visual representation of modulated speech sounds. Speech envelope has a crest factor of +12 dB & valleys of - 18 dB. These two lines define the representative dynamic range of normal
conversational speech over time (a 10 sec. measurement)

Question 17

Calculate threshold-based insertion gain requirements using the “half gain” fitting formula

Answer 17

“half gain”: most people wanted gain that equaled 1/2 the threshold of the loss (take loss and divide by 2, tells you amount of gain)

Question 18

Differentiate frequency shaping band adjustments from compression shaping channel adjustments

Answer 18

“Frequency-shaping bands” increase or decrease “gain” until the prescriptive target is reached. Gain is adjusted as a frequency shaping band until output matches prescriptive target. COLUMNS, done first

Compression shaping channels are adjusted until the prescriptive target for THAT input level is reached. ROWS

Question 19

Prescriptive targets

Answer 19

specify the REIG (GAIN) or REAR (OUTPUT) needed at each audiometric frequency Verification: the process that lets us see if our prescriptive formula provided the output we wanted!
Validation: the process that lets us see if the patient thinks our choices were beneficial

Question 20

RESR

Answer 20

(Real ear saturation response) the frequency response of a hearing instrument, measured in the ear canal, with an input signal sufficiently intense to operate the hearing instrument at its MPO (watch patient’s face!)

Question 21

REUR: test protocol and objectives

*HL

Answer 21

1. Insertion gain
2. enter instrument style
3. Set PRESENTATION to SINGLE or
   DOUBLE view
4. Set FORMAT to GRAPH (not CHART)
5. Set SCALE to HL
6. enter audiogram thresholds
   - select transducer used in testing
   -set REUR to MEASURE
   -enter thresholds

*improves accuracy of prescriptive fitting by knowing an individual’s ear canal resonance It changes by ear canal differences

Question 22

REOR: test protocol and objectives

*SPL

Answer 22

• with earmold in, make sure HA is off
  1. on ear
  2. speech map
  3. format: graph
  4. hide/show box: unaided–> show

To verify: the degree of vent effect, actual transparency of open dome fit, and degree of occlusion

Green: unoccluded
Pink: occluded

Question 23

Occlusion Effect test: test protocol and objectives

-Vent management options

Answer 23

“Occlusion” scale indicates the degree of occlusion in dB SPL
Instructions:
1. Insert probe tube in canal
2. Place device in ear- muted or off
3. Patient vocalizes “eee” at moderate vocal effort
4. Press “stop test” to capture OE

Vent management:
OE reduces by 4 DB for
every 1 mm increase in
vent diameter

*if there is a small difference between probe mic and reference mic and its green, then there is no occlusion. If it is red and there is a big difference, there is occlusion.

Question 24

Purpose of adjustments to frequency shaping bands vs. compression shaping channels
-protocol associated with each adjustment

Answer 24

“first fit” isn’t good

Frequency shaping bands (COLUMNS)=AUDIBILITY

“target matching”: highlight all gain values and raise and lower them as needed, adjust the overall gain until the LTASS falls within +/- 5 dB of a target

Compression shaping channels : adjust compression ratio to optimize detection of soft input signals or reduce loud input signals for increased comfort (ROWS)

Question 25

MPO: test protocol and objectives

Answer 25

Purpose: to ensure tolerance of loud input signals | *Patient says loud and comfortable or loud but okay

Question 26

Interpretation of SpeechMap speech envelope graphic response

Answer 26

If we adjust gain for a 50dB input signal, the bottom half of the speech envelope is adjusted. If we adjust gain for a 75dB signal, the top part of the speech envelope is adjusted.

Question 27

Which prescription provides targets for tonal languages?

Answer 27

NAL-NL2 | *Low frequencies are more important in these languages

Question 28

Which formula supplies MPO targets

Answer 28

DSL (Desired Sensation Level)

Question 29

Loudness Normalization rationale and prescriptive formula approach. Which prescriptive formula follows this philosophy?

Answer 29

Theorizes aided loudness perception should be the same as the normal loudness perception. DSL (desired sensation level)

Question 30

DSL formula settings for mild vs. severe hearing losses; pediatric vs. adult?

Answer 30

- Sets a low TK (~30 dB SPL) for milder losses - Sets a higher TK (~60 dB SPL) for severe hearing loss - Applies of expansion to low input levels - Uses multi-stage WDRC compression to expand DR - Uses output compression limiting to high input levels DSL 5.0’s adult fitting formula version reduces mid-frequency gain by 7 dB

Question 31

Loudness Equalization rationale and prescriptive formula approach. Which prescriptive formula follows this philosophy?

Answer 31

Theorizes aided loudness of high frequency signal should be equal to low frequencies, even if perceived loudness is different than normal loudness perception. This formula adds more gain to HF input signals, so they seem as loud as low frequencies. This boosts high frequency output to improve audibility of high- frequency sounds NAL (National Acoustic Library)

Question 32

NAL formula for REIG settings for mild to moderate vs. severe losses

Answer 32

It uses pure-tone threshold to create REIG "gain targets" NAL-R is better for mild to moderate HL because people with severe to profound HL require additional gain and less high frequency emphasis. NAL-RP is better for severe losses because they required more gain and less high frequency emphasis. More low frequency gain provides power and less high frequency gain helps to deal with feedback issues.

Question 33

Which formula supports language development?

Answer 33

DSL 5.0 - Sets a low TK (~30 dB SPL) for milder losses - Sets a higher TK (~60 dB SPL) for severe hearing loss - Too much gain of soft input signals results in a loss of intelligibility for this population - Applies of expansion to low input levels - Uses multi-stage WDRC compression to expand DR - Uses output compression limiting to high input levels - DSL 5.0’s adult fitting formula version reduces mid-frequency gain by 7 dB

Question 34

What does it mean when a prescriptive formula is proprietary?

Answer 34

Each brand has their own "name-brand" prescription

Question 35

Is it acceptable for an audiologist to change the prescription, applying gain that does not meet the "+/- 5 dB for target" criteria?

Answer 35

Yes because they are asking the patient what they think needs to be adjusted and the prescription is just a starting place

Question 36

Patient desires increased intelligibility

Answer 36

Choose NAL-NL2

Question 37

Patient desires increased comfort or REUR is not average

Answer 37

DSL 5.0

Question 38

Audibility SII Scores

Answer 38

conversational, 65dB signal: ~70% SII soft, 50dB signal: ~35-40% SII loud, 75dB signal: Threshold +LDL/2= target for loud signals

Question 39

REMEMBER:

Answer 39

Always adjust frequency shaping bands first, and compression shaping channels second. Always select the broadest frequency range possible when you adjust program. Don't forget to include all the low frequencies and high frequencies.

Question 40

Consider which portion of the speech envelope you're changing with each adjustment

Answer 40

Top of envelope: 75 dB | Bottom of envelope: 50 dB

Question 41

Define channel interactions. Keep in mind that adjustments to one channel will impact adjacent channels

Answer 41

The slope of one frequency channel overlaps adjacent frequencies Channel interaction: occurs when adjustments to one frequency pulls down adjacent frequencies Solution: adjust a slightly narrower frequency range knowing that adjacent frequencies will adjust too

Question 42

Recognize the impact reference microphone contamination has on programming

Answer 42

When amplified output escapes out of canal from large vents and open domes it contaminates the reference microphones measurement of the input signal Result: the reference microphone’s unit analyzer reduces the intensity of the test signal and underestimates the device output Solution: “stored equalization” calibration method