HIS Pure Tone & Speech Audiometry 1 — Questions and Answers
Question 1: What does pure tone audiometry primarily assess?
- Speech discrimination ability
- Hearing threshold across frequencies (Correct answer)
- Middle ear pressure
- Otoacoustic emissions
Correct answer: Hearing threshold across frequencies
Pure tone audiometry is a fundamental hearing test that measures a person's hearing sensitivity for specific pure tones (single frequencies). It determines the softest sound (threshold) an individual can hear at various frequencies, typically ranging from 250 Hz to 8000 Hz. This provides a detailed audiogram, which is a graphical representation of their hearing thresholds, helping to identify the type, degree, and configuration of hearing loss.
Question 2: Which unit is used to measure hearing thresholds?
- Hz
- Watts
- dB HL (Correct answer)
- dB SPL
Correct answer: dB HL
Hearing thresholds are measured in decibels Hearing Level (dB HL), which is a standardized unit used in audiometry. dB HL references the average hearing threshold of young, healthy adults, meaning 0 dB HL represents normal hearing. This unit allows for a consistent comparison of an individual's hearing ability against a normative standard, making it the appropriate unit for reporting hearing thresholds.
Question 3: What is the purpose of masking during pure tone audiometry?
- Reduce background noise
- Test both ears at once
- Isolate the test ear (Correct answer)
- Measure speech clarity
Correct answer: Isolate the test ear
Masking is a critical procedure used during pure tone audiometry to prevent the non-test ear from hearing the sound presented to the test ear. When the sound presented to the test ear is loud enough to cross over to the non-test ear, masking introduces a narrow-band noise to the non-test ear. This ensures that the measured threshold accurately reflects the hearing ability of only the ear being tested, preventing false results and ensuring test validity.
Question 4: Which frequencies are commonly tested in a standard pure tone audiogram?
- 20 Hz to 100 Hz
- 250 Hz to 8000 Hz (Correct answer)
- 9000 Hz to 12000 Hz
- 10,000 Hz to 20,000 Hz
Correct answer: 250 Hz to 8000 Hz
A standard pure tone audiogram typically tests hearing thresholds at octave and inter-octave frequencies ranging from 250 Hz to 8000 Hz. This range covers the most critical frequencies for understanding human speech and environmental sounds. Testing these specific frequencies provides a comprehensive overview of a person's hearing ability across the speech banana and helps characterize the nature of any hearing loss.
Question 5: What does the speech recognition threshold (SRT) assess?
- Ability to detect pure tones
- Understanding of whispered words
- Minimum intensity to repeat words (Correct answer)
- Response to high frequencies
Correct answer: Minimum intensity to repeat words
The Speech Recognition Threshold (SRT) assesses the softest level at which a person can correctly identify and repeat 50% of spondee words (two-syllable words with equal stress). It is a measure of hearing sensitivity for speech and serves as a valuable cross-check for pure tone average thresholds. The SRT helps confirm the reliability of pure tone results and provides insight into a person's ability to detect speech.
Question 6: What does a flat audiogram indicate?
- Normal hearing
- Sensorineural hearing loss
- Conductive loss in one ear
- Uniform hearing loss (Correct answer)
Correct answer: Uniform hearing loss
A flat audiogram indicates that a person has a similar degree of hearing loss across all tested frequencies, meaning the hearing thresholds are relatively consistent from low to high frequencies. This pattern suggests a uniform hearing loss, where sounds of all pitches are perceived with similar difficulty. It contrasts with sloping or rising audiograms, which show varying degrees of loss across the frequency range.
Question 7: What is the purpose of bone conduction testing?
- Check eardrum flexibility
- Identify auditory neuropathy
- Bypass outer and middle ear (Correct answer)
- Evaluate speech clarity
Correct answer: Bypass outer and middle ear
Bone conduction testing is performed by placing a vibrator on the mastoid bone or forehead, which directly stimulates the cochlea, bypassing the outer and middle ear. This method assesses the function of the inner ear (cochlea) and auditory nerve, independent of any issues in the outer or middle ear. By comparing bone conduction thresholds to air conduction thresholds, audiologists can differentiate between conductive, sensorineural, and mixed hearing losses.
Question 8: Which symbols are used for air conduction on an audiogram?
- Squares and triangles
- O and X (Correct answer)
- Dots and slashes
- Stars and arrows
Correct answer: O and X
On a standard audiogram, 'O' symbols are used to represent air conduction thresholds for the right ear, typically plotted in red. 'X' symbols are used for air conduction thresholds for the left ear, typically plotted in blue. These standardized symbols allow for clear and consistent interpretation of hearing test results across different clinicians and settings, ensuring universal understanding of the audiogram.
Question 9: What does word recognition testing evaluate?
- Balance function
- Loudness discomfort levels
- Ability to repeat words correctly (Correct answer)
- Tympanic membrane movement
Correct answer: Ability to repeat words correctly
Word recognition testing, also known as speech discrimination or speech recognition score, evaluates a person's ability to correctly identify and repeat single-syllable words presented at a comfortable listening level. This test assesses the clarity of hearing and how well an individual can understand speech, even when it is audible. It provides crucial information about the impact of hearing loss on communication and helps predict hearing aid benefit.
HIS Pure Tone & Speech Audiometry 1
What does pure tone audiometry primarily assess?