Week7 Flashcards
Effect of Conductive Loss
Loss of audibility
Effect of Sensorineural Loss
-Loss of audibility
-Loss of clarity
Pure-Tone Audiometry Information
-Detection of Important frequencies
-Degree
-Type
-Configuration
Speech Audiometry Information
-Stimuli to characterize patient’s ability to hear spoken language
Recorded Materials Advantage
-Standardized talker speed
-Standardized talker vocal effort
-Standardized talker dialect/accent
Monitored Live Voice Advantage
-More flexibility in presentation of materials
-Faster presentation
-Engaging with younger children
Hierarchy of auditory skills and their Components
Lowest to highest:
-Detection: Determine presence/absence
->Discrimination: Distinguish between two or more sounds
->Recognition: Identify/Label
->Understanding: Comprehend the meaning
Speech Detection Threshold (SDT) Definition
lowest intensity level (dB HL) that pt can detect speech.
SDT Stimuli
Words, or continuous speech
Why we use SDT
If pt cannot repeat back words
Speech Recognition Threshold (SRT) Definition
Lowest intensity level (dB HL) that pt can correctly repeat words
SRT Stimuli
Spondees (two-syllable words with equal stress)
Why we use SRT
When pt can repeat back words
SRT/PTA Relationship
SRT & PTA within +/- 10 dB, if not poor reliability.
SDT/Lowest threshold Relationship
SDT within +/- 10 of lowest threshold of 250 to 4000 Hz
Word Recognition Testing Definition
Assesses pt’s ability to correctly identify spoken words presented above threshold
Word recognition Testing Stimuli
Monosyllabic Words
Word Recognition Testing Presentation Level
40 dB sensation level (dB SL) (add 40 to SRT)
WRT Score categories
90-100% = excellent,
80-89% = good,
70-79%=Fair,
60-69%=poor,
<60% = very poor
Expected performance-intensity function for normal vs. conductive vs. sensory vs. neural/retrocochlear loss
-normal=100% correct around 40 dB above SRT. -Conductive= reaches 100% correct around 40 dB above SRT, but at a higher intensity than normal hearing.
-Sensory (cochlear)= does not reach 100% even at high intensity levels.
-Neural (retrocochlear)= as intensity increases, performance reaches a point where it starts to decrease.
Signal-to-noise ratio: How to compute if given a signal and noise level
Speech – Noise= S-to-N ratio in dB
Cross-Hearing Definition
Sound presented to one ear can reach the opposite cochlea via bone conduction
interaural attenuation
The decibel reduction in sound intensity that reaches the opposite cochlea
Values of interaural attenuation
-Insert earphones = 50 dB, -supra-aural headphones = 40 dB,
-bone oscillator = 0 dB
For a given intensity level and a given transducer, determine the intensity level that reaches the opposite cochlea
intensity level of tone minus interaural attenuation = tone reaching opposite cochlea
What happens if we fail to mask for air conduction and for bone conduction
We will underestimate the threshold.
symbols for masked air conduction and masked bone conduction thresholds
Right masked air conduction= triangle (tone in right ear, masking noise in left),
left masked air conduction = Square (tone in left ear, masking noise in right ear),
Right masked bone conduction = square bracket eating the bar to the right (oscillator on right mastoid, masking tone via air conduction in left),
Left masked bone conduction = square bracket eating the bar to the left (bone oscillator on left mastoid, masking tone in right ear)
determine the degree of hearing loss based on masked thresholds
use masked thresholds for degree if present!
determine if masking is needed for air-conduction and for bone conduction
air=if difference between air conduction threshold in test ear and bone conduction threshold in opposite ear is greater than or equal to interaural attenuation.
Bone=when ac threshold and unmasked bc threshold in same ear is greater than or equal to 15 dB
