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
