AUDIOLOGY - EVALUATION ALL TESTS (AB) Flashcards
Which aspects should be inspected first during an ear examination?
Changes in auricle shape, surgical scars, crusting, discharge (cerumen, mucus, pus, blood, CSF), redness, and swelling.
What are the tools for hearing evaluation?
Tuning fork test, pure tone audiometry, speech audiometry, tympanometry, brainstem-evoked response audiometry (BERA - gold standard).
What are the degrees of hearing loss?
Mild, moderate, severe.
What are the reference comparisons in a tuning fork test?
Examiner’s ear (standard/golden ear), patient’s normal ear (for unilateral hearing loss), third person with normal hearing acuity.
What is measured in a tuning fork test?
Threshold of hearing by comparing when the patient and examiner stop hearing the sound.
What is the Weber’s test used for?
Determining lateralization of hearing loss.
How is Weber’s test performed?
A vibrating tuning fork is placed on the midline of the forehead, vertex of the skull, or incisors, and the patient is asked where they hear the sound best.
What does lateralization to the poorer ear in Weber’s test indicate?
Conductive hearing loss (attenuation of background noise and prevention of energy loss from the external auditory canal).
What does lateralization to the better ear in Weber’s test indicate?
Sensorineural hearing loss (or normal hearing in both ears/equal conductive hearing loss).
What does the Rinne’s test compare?
Bone conduction (BC) vs air conduction (AC).
How is Rinne’s test performed?
A vibrating tuning fork is placed on the mastoid process until the sound is no longer heard, then moved near the external auditory canal.
What is a positive Rinne’s test?
AC > BC, indicating normal hearing or sensorineural impairment.
What is a negative Rinne’s test?
AC < BC, indicating conductive hearing loss.
Why is masking necessary in Rinne’s test?
To prevent the opposite ear from detecting sound through bone conduction, avoiding false-negative results.
What is the Schwabach’s test used for?
Comparing the patient’s bone conduction against a normal reference.
How is Schwabach’s test performed?
A vibrating tuning fork is placed on the mastoid process of the patient until inaudible, then applied to a normal reference ear.
What does a prolonged Schwabach’s test result indicate?
Conductive hearing loss (EAC/ME pathology).
What does a diminished Schwabach’s test result indicate?
Sensorineural hearing loss (cochlear/retrocochlear pathology).
What is the Bing’s test used for?
Assessing the occlusion effect.
How is Bing’s test performed?
A vibrating tuning fork is placed on the mastoid while the examiner alternately occludes and opens the external auditory canal by pressing on the tragus.
What is a positive Bing’s test?
Increase in loudness when ear is covered and decrease when opened, indicating normal or sensorineural hearing loss.
What is a negative Bing’s test?
No change in loudness, indicating conductive hearing loss.
What are the limitations of tuning fork tests?
Subjectivity in detecting inaudibility, difficulty in reproducibility, background noise interference, and skull vibration stimulating both cochleae.
Why is the 256 Hz tuning fork preferred?
It is the most accurate for detecting slight conductive hearing loss.
Why is the 512 Hz tuning fork preferred?
It is more useful for Bing’s test.
Why can tuning fork tests produce false results?
Bone conduction vibrates the entire skull, allowing sound to be heard in both ears, leading to false positives/negatives.
Why is it recommended to use multiple tuning fork tests?
To improve accuracy by cross-checking results due to the unreliability of single tests.
What technological advancement in the early 1920s made pure tone audiometry possible?
The invention of vacuum tubes to produce electronic tones.
Which frequencies are sampled in pure tone audiometry that represent the spectrum of human hearing capability?
125, 250, 500, 1000, 2000, 4000, and 8000 Hz.
What are the half-octave interval frequencies provided in pure tone audiometry?
750, 1500, 3000, and 6000 Hz.
What is the advantage of pure tone audiometry regarding tonal intensity?
Tonal intensity can be maintained at a fixed level or interrupted at will at fixed intervals.
Name the three essential parts of pure tone audiometry (PTA).
- Variable frequency oscillator, 2. Attenuator, 3. Transducer.
What is the function of a variable frequency oscillator in PTA?
To produce sounds with changeable frequencies.
What role does the attenuator play in PTA?
It changes the volume to permit variations in intensity of the sound.
What is the purpose of a transducer in PTA?
To convert electrical energy to acoustic energy using devices like earphones, bone vibrators, or loudspeakers.
What is an audiogram?
A graph of the patient’s hearing sensitivity for various frequencies.
How are measures recorded on an audiogram?
Separately for each ear, with frequency on the x-axis (abscissa) and intensity on the y-axis (ordinate).
Define ‘threshold’ in the context of audiometry.
The lowest intensity level in dB that can be heard for each frequency.
What is ‘Audiometric Zero (ANSI)’?
The median average threshold of a large sample of young adults with no hearing complaints, representing 0 dB HL.
What does it indicate when bone conduction thresholds are better than air conduction by 10 dB or more and are normal?
The hearing loss is conductive.
What type of hearing loss is indicated when bone conduction thresholds are the same as air conduction and neither is normal?
Sensorineural hearing loss.
If bone conduction thresholds are reduced but still better than air conduction by 10 dB or more, what type of hearing loss is this?
Mixed or combined hearing loss.
What does the horizontal axis on an audiogram represent?
Frequencies (Hz), ranging from 250 to 8000 Hz.
What does the vertical axis on an audiogram represent?
Intensity of the sounds (dB).
What is considered a normal hearing threshold in dB?
0-20 dB is considered normal; clinically, up to 25 dB is acceptable.
What dB range indicates mild hearing loss?
20-40 dB.
What dB range indicates moderate hearing loss?
40-60 dB.
What dB range indicates severe hearing loss?
60-80 dB.
What dB range indicates profound hearing loss?
80-100 dB.
In audiogram color coding, which color represents the right ear?
Red.
In audiogram color coding, which color represents the left ear?
Blue.
What symbol is typically used to represent air conduction in the right ear on an audiogram?
A circle (O).
What symbol is typically used to represent air conduction in the left ear on an audiogram?
An ‘X’.
What does a ‘Carhart’s notch’ at 2000 Hz on an audiogram suggest?
It is a signature for otosclerosis.
What does a notch at 4000 Hz on an audiogram typically indicate?
Noise-induced hearing loss.
What does pure tone audiometry (PTA) measure?
The ability to hear various tones, typically beeps or warbles, across different frequencies.
Why is speech audiometry important in hearing assessments?
It evaluates the ability to understand speech, which is crucial for effective communication.
What is the purpose of masking the non-test ear during speech audiometry?
To prevent crossover hearing, ensuring accurate assessment of each ear individually.
How does Speech Reception Threshold (SRT) differ from Pure Tone Audiometry (PTA)?
SRT measures sensitivity using words, while PTA uses tones; SRT assesses the lowest level at which speech can be recognized 50% of the time.
What type of words are used in determining the Speech Reception Threshold?
Spondee words, which are two-syllable words with equal stress on each syllable.
How is the Spondee Threshold defined?
The faintest presentation level in dB at which the patient correctly identifies 50% of the test words.
Which pure tone frequencies does the Spondee Threshold closely agree with?
500, 1000, and 2000 Hz, as these frequencies are commonly used in human speech.
What might a difference of 15 dB or more between the Spondee Threshold and Pure Tone Average indicate?
Possible equipment calibration error, patient misunderstanding, lack of cooperation, or malingering.
What does Speech Discrimination Testing assess?
The patient’s ability to understand speech, aiding in diagnosing the site of lesion and planning rehabilitation.
What type of word lists are used in Speech Discrimination Testing?
Phonetically balanced, single-syllable word lists that reflect the relative incidence of various speech sounds in the chosen language.
At what level are words presented during Speech Discrimination Testing?
20 to 40 dB above the Speech Reception Threshold or at the patient’s most comfortable level.
What is considered a normal score in Speech Discrimination Testing?
94-100% correct word recognition.
What does Tympanometry measure?
The compliance (mobility) of the tympanic membrane and ossicular chain system under varying air pressures, assessing middle ear function.
What does a Type A tympanogram indicate?
Normal middle ear pressure with maximum compliance near ambient air pressure.
What condition might a Type AS tympanogram suggest?
Fixation or stiffening of the ossicular system, as it shows normal pressure but reduced compliance.
What does a Type AD tympanogram signify?
Very high compliance at ambient pressure, possibly indicating ossicular discontinuity or a monomeric tympanic membrane.
What does a Type B tympanogram typically indicate?
A flat curve suggesting middle ear fluid, a thickened drum, or impacted cerumen.
What might a Type C tympanogram reveal?
Maximum compliance at negative pressure, often associated with a retracted tympanic membrane or Eustachian tube dysfunction.
