Exam 2 Flashcards
Setup for speech audiometry
What is the speech reception threshold?
Lowest level an individual can identify spondees:
- 3 repeated times
- 50% of the time (2/4)
- 75% of the time (3/4)
What stimulus is used to determine the speech reception threshold?
Central Institute for the Deaf (CID) W-1: two-syllabic words (spondees) with equal stress
What is the purpose of speech reception threshold testing?
- Validates PTA (500, 1000 & 2000 Hz)
- Baseline for speech discrimination test
- Hearing aid evaluation for gain (amplification) prescription
What is the procedure for finding the speech reception threshold?
- Starting intensity level: 30 dB above the PTA for each ear
- Keep going down 10 dB until there’s no response, then go up 5 dB
- repeat until you reach threshold
- Presentation mode is usually live voice
- “Say the word ______.”
What are the criteria for SRT to validate PTA?
PTA and SRT should be within +/- 10 dB
Why might PTA and SRT be more than 10 dB apart?
- PTA might be invalid—try using Fletcher/two-freq. average
- Incorrect test procedure
- Improper test equipment/calibration
- Functional hearing loss—they’re faking!
What is another name for speech discrimination testing?
Word recognition testing
What is the purpose of speech discrimination (SD) testing?
- Determine extent of speech discrimination ability
- Determine site of ear pathology
- Determine candidacy for hearing aid amplification
- Determine prognosis for aural rehabilitation
What is the procedure for SD testing?
- Start at (and stay at) 30 dB above SRT in each ear
- Present monosyllabic phonetically-balanced (PB) words via CD
- **25 **words presented
Open vs. closed word lists
-
Open: repeat the words
- CID W-22 (Central Institute for the Deaf)
- NU-6(Adu) (Northwestern University)
-
Closed: patient has word lists/pictures
- WIPI (Word Intelligibility by Picture Identification)
Differences between SRT and SD
Interpretation of different SD scores
-
90-100%: Excellent
- Normal Hearing/Conductive Hearing Loss
-
60-89%: Moderate to Fair
- Sensorineural loss (Cochlear lesion)
-
0-59%: Very poor
- Sensorineural loss (Neural/8th nerve lesion)
SD at higher intensities
- Extension of SD testing
- Like a stress test for auditory system
SD in noise
- Ex: SPIN test (Speech Perception in Noise)
- More generalizable
SD using synthetic sentences
- Ex: SSI test (Synthetic Sentence Identification
- Closed test (identify from a list of sentences)
- Synthetic so it’s less predictable
- Used with auditory processing disorders
SD using high-frequency stimuli
- Ex: CCT (California Consonant Test)
- Used in patients w/ selective high frequency loss (greater than 2 kHz)
- Sensitive to high frequency consonant sounds
PI-PB Function procedure
- Performance Intensity—Phonetically Balanced
- Measures SD performance @ different intensity levels
- Uses PB words (CID W-22 or NU-6)
- Uses the following intensities:
- 30 dB SL
- 45 dB SL
- 60 dB SL
What is meant by SL?
- Sensation Level
- A level above the threshold
- If SRT threshold = 20 dB, 30 dB SL = 50 dB
How does PI-PB function differ between conductive, cochlear, and neural loss?
- As you increase the intensity in conductive or cochlear loss, performance improves
- As you increase the intensity in neural loss, performance decreases
- Nerve can’t conduct sounds to the brain
What is the formula for PI-PB rollover ration (ROR)
How do we interpret PI-PB Roll over Ratio?
- 0.4 or less: normal/conductive/SN cochlear
- Greater than 0.4: neural lesion
What is the purpose of Immittance Audiometry?
Directly evaluates middle ear status
- Tympanometry
- Stapedial reflex threshold
Indirectly evaluates inner ear status
- Stapedial reflex threshold
- Stapedial reflex decay
What are some advantages of immittance audiometry?
- It’s objective, so it’s replicable and requires less patient cooperation
- Determines cause for conductive hearing loss
- Determines functional integrity of the inner ear
Immittance Audiometry: Probe Ear vs. Phone ear
Probe ear
- Test ear
Phone ear
- Earphone ear
- Presents sounds to elicit contralateral stapedial reflex
Intensity/frequency levels for immittance audiometry
- Probe tone frequency: 220 Hz or 660 Hz
- (use 660 with babies less than 1)
- Probe tone intensity: 85 dB SPL in the ear canal
What is plotted on a tympanogram?
- Compliance (= mobility): Y axis
- Pressure: X axis
Type A tympanogram
- Normal
- Peak compliance around 0 to -100 mm air pressure (0.3 to 1.8 mL)
Type AS tympanogram
- Stiffness/Shallow peak
- Limited peak compliance around 0 to -100 mm air pressure (< 0.3 mL)
- Consistent with otosclerosis (stapedial bone is fixed to oval window)
Type AD tympanogram
- Flaccidity
- Disarticulation of ossicles
- Deep
- Abnormally high compliance (hypercompliance) around 0 to -100 mm air pressure (> 1.8 mL)
Type B tympanogram
- Middle ear fluid buildup
- Abnormally low compliance
- Peak compliance absent (flat line)
Type C tympanogram
- Eustachian tube malfunction
- Normal-height peak below -100 mm air pressure
- Ear is “plugged up”
What are normal values for ear canal volume?
0.2 to 2.0 mL
What are normal values for peak compliance in tympanometry?
0.3 to 1.8 mL
What are normal values for middle ear air pressure in tympanometry?
-100 to +50 mm
What might we see in tympanometry for someone with an eardrum perforation?
- Abnormally high ear canal volume (> 2.0 mL)
- Low compliance on tympanogram (type B)
How do we calculate SD?
SD (%) = # correct x 4
Air Conduction Audiometry: symbols for plotting a/c thresholds
Hearing loss classifications for children 5 and under
0-15 dB HTL - Normal
16-30 dB HTL - Mild
31-50 dB HTL - Moderate
51-80 dB HTL - Severe
>81 dB HTL - Profound
Hearing loss classifications for children older than 5 & adults
0-25 dB HTL - Normal
26-40 dB HTL - Mild
41-55 dB HTL - Moderate
56-70 dB HTL - Moderate-Severe
71-90 dB HTL - Severe
>91 dB HTL - Profound
How will a/c and b/c thresholds differ for people with sensorineural, conductive, or mixed hearing loss?
- Sensorineural: a/c and b/c both abnormal, equally affected
- Conductive: a/c normal, b/c abnormal
- Mixed: a/c and b/c both abnormal, a/c worse (passes through two damaged areas)
