CA HA Dispensing Written Exam 2025 —
Full Exam with verified answers and
rationale graded A+
Section 1: Anatomy and Physiology of the Auditory System (Questions 1–25)
1. The ossicles of the middle ear include which three bones?
A. Malleus, incus, stapes
B. Hammer, nail, bone
C. Cochlea, vestibule, semicircular canals
D. Malleus, stapes, cochlea
Answer: A
Rationale: The three ossicles are the malleus (hammer), incus (anvil), and stapes (stirrup). They
transmit vibrations from the tympanic membrane to the inner ear -13.
2. What is the primary function of the outer ear?
A. To amplify sound
B. To collect and funnel sound waves to the eardrum
C. To transmit signals to the brain
D. To produce cerumen
Answer: B
Rationale: The outer ear (pinna and ear canal) captures sound waves and channels them through the
ear canal to the tympanic membrane -13.
3. What structure is found at the bottom of the ear canal?
A. The Vagus Nerve (Xth Cranial)
B. The chorda tympani
C. The stapedius muscle
D. Jacobson's nerve
Answer: A
Rationale: The Vagus Nerve (Xth Cranial) is located at the bottom of the ear canal and can be
stimulated during ear canal procedures -3.
4. The tympanic membrane is approximately what size?
A. 5 mm
B. 9 mm
C. 15 mm
D. 20 mm
Answer: B
Rationale: The tympanic membrane is approximately 9 mm (about 1/4 inch high and 3/8 inch wide,
roughly the size of a paper punch hole) -8.
,5. What is the average length of the adult ear canal?
A. 0.5 inch
B. 1 inch to 1 3/8 inch
C. 2 inches
D. 0.25 inch
Answer: B
Rationale: The ear canal is approximately 1 inch to 1 3/8 inches long with a diameter of about 0.7 cm
(1/4 inch) -8.
6. Which cranial nerve is responsible for hearing?
A. Cranial Nerve V (Trigeminal)
B. Cranial Nerve VII (Facial)
C. Cranial Nerve VIII (Vestibulocochlear)
D. Cranial Nerve X (Vagus)
Answer: C
Rationale: The vestibulocochlear nerve (CN VIII) carries auditory and vestibular information from the
inner ear to the brain.
7. What is the function of the Eustachian tube?
A. To transmit sound vibrations
B. To equalize pressure between the middle ear and nasopharynx
C. To produce cerumen
D. To house the ossicles
Answer: B
Rationale: The Eustachian tube connects the middle ear to the nasopharynx and equalizes air
pressure on both sides of the tympanic membrane.
8. The organ of Corti is located in which structure?
A. Semicircular canals
B. Cochlea
C. Vestibule
D. Middle ear
Answer: B
Rationale: The organ of Corti is the sensory organ of hearing located within the cochlea of the inner
ear.
9. What type of hearing loss results from damage to the inner ear or auditory nerve?
A. Conductive
B. Sensorineural
C. Mixed
D. Mechanical
Answer: B
Rationale: Sensorineural hearing loss results from damage to the hair cells in the cochlea or the
auditory nerve -13.
10. Conductive hearing loss is caused by problems in which part(s) of the ear?
A. Inner ear only
,B. Outer or middle ear
C. Auditory nerve
D. Cochlea
Answer: B
Rationale: Conductive hearing loss occurs when sound is not efficiently conducted through the outer
or middle ear to the inner ear.
11. Which of the following is a symptom commonly associated with sensorineural hearing loss?
A. Ear fullness
B. Tinnitus
C. Normal speech discrimination in noise
D. Improved hearing in noise
Answer: B
Rationale: Tinnitus, difficulty understanding speech in noise, and reduced speech discrimination are
typical symptoms of sensorineural hearing loss. Ear fullness is more commonly associated with
conductive or middle-ear pathology -18.
12. What does the term "recruitment" refer to in audiological testing?
A. The process of hiring new staff
B. Abnormally rapid growth of loudness perception
C. The ability to hear soft sounds but not loud ones
D. A type of tympanometry result
Answer: B
Rationale: Recruitment is an abnormal phenomenon, typically in sensorineural hearing loss, where a
small increase in stimulus intensity above threshold produces an abnormally large increase in
perceived loudness -16.
13. What is presbycusis?
A. Hearing loss caused by noise exposure
B. Age-related hearing loss
C. Hearing loss caused by ototoxic drugs
D. Congenital hearing loss
Answer: B
Rationale: Presbycusis is age-related hearing loss, typically characterized by bilateral, high-frequency
sensorineural loss.
14. The stapedius muscle contracts in response to:
A. Soft sounds
B. Loud sounds
C. Low-frequency sounds only
D. Bone conduction stimulation only
Answer: B
Rationale: The stapedius muscle contracts in response to loud sounds as part of the acoustic reflex,
stiffening the ossicular chain to reduce sound transmission.
15. When both stapedius muscles contract even though only one ear is stimulated, this is called:
A. Ipsilateral reflex
, B. Contralateral reflex
C. Consensual reflex
D. Bilateral reflex
Answer: C
Rationale: The consensual reflex occurs when both stapedius muscles contract even though only one
ear is stimulated -3.
16. What is the primary function of the pinna?
A. To amplify high frequencies
B. To collect sound and assist in localization
C. To produce cerumen
D. To equalize pressure
Answer: B
Rationale: The pinna collects sound waves and assists with sound localization, particularly for
determining the elevation of sound sources.
17. Which frequency range is most affected by a head cold?
A. High frequencies (2000–8000 Hz)
B. Low frequencies (250–500 Hz)
C. Ultra-high frequencies (above 8000 Hz)
D. All frequencies equally
Answer: B
Rationale: A head cold often causes middle ear effusion or Eustachian tube dysfunction, which
primarily affects low-frequency hearing (250–500 Hz) -3.
18. What is the significance of the air-bone gap?
A. It indicates sensorineural hearing loss
B. It indicates a difference between air and bone conduction thresholds
C. It measures speech discrimination
D. It measures loudness discomfort levels
Answer: B
Rationale: An air-bone gap is the difference between air conduction and bone conduction
thresholds, indicating a conductive component to hearing loss.
19. A significant air-bone gap is defined as a difference of how many decibels at 2 or more
consecutive frequencies?
A. 5 dB
B. 10 dB
C. 15 dB
D. 20 dB
Answer: C
Rationale: A significant air-bone gap is a difference of 15 decibels or more between air conduction
and bone conduction thresholds at 2 or more succeeding octave frequencies from 500 Hz through
4000 Hz -1-8.
20. The semicircular canals are responsible for:
A. Hearing
Full Exam with verified answers and
rationale graded A+
Section 1: Anatomy and Physiology of the Auditory System (Questions 1–25)
1. The ossicles of the middle ear include which three bones?
A. Malleus, incus, stapes
B. Hammer, nail, bone
C. Cochlea, vestibule, semicircular canals
D. Malleus, stapes, cochlea
Answer: A
Rationale: The three ossicles are the malleus (hammer), incus (anvil), and stapes (stirrup). They
transmit vibrations from the tympanic membrane to the inner ear -13.
2. What is the primary function of the outer ear?
A. To amplify sound
B. To collect and funnel sound waves to the eardrum
C. To transmit signals to the brain
D. To produce cerumen
Answer: B
Rationale: The outer ear (pinna and ear canal) captures sound waves and channels them through the
ear canal to the tympanic membrane -13.
3. What structure is found at the bottom of the ear canal?
A. The Vagus Nerve (Xth Cranial)
B. The chorda tympani
C. The stapedius muscle
D. Jacobson's nerve
Answer: A
Rationale: The Vagus Nerve (Xth Cranial) is located at the bottom of the ear canal and can be
stimulated during ear canal procedures -3.
4. The tympanic membrane is approximately what size?
A. 5 mm
B. 9 mm
C. 15 mm
D. 20 mm
Answer: B
Rationale: The tympanic membrane is approximately 9 mm (about 1/4 inch high and 3/8 inch wide,
roughly the size of a paper punch hole) -8.
,5. What is the average length of the adult ear canal?
A. 0.5 inch
B. 1 inch to 1 3/8 inch
C. 2 inches
D. 0.25 inch
Answer: B
Rationale: The ear canal is approximately 1 inch to 1 3/8 inches long with a diameter of about 0.7 cm
(1/4 inch) -8.
6. Which cranial nerve is responsible for hearing?
A. Cranial Nerve V (Trigeminal)
B. Cranial Nerve VII (Facial)
C. Cranial Nerve VIII (Vestibulocochlear)
D. Cranial Nerve X (Vagus)
Answer: C
Rationale: The vestibulocochlear nerve (CN VIII) carries auditory and vestibular information from the
inner ear to the brain.
7. What is the function of the Eustachian tube?
A. To transmit sound vibrations
B. To equalize pressure between the middle ear and nasopharynx
C. To produce cerumen
D. To house the ossicles
Answer: B
Rationale: The Eustachian tube connects the middle ear to the nasopharynx and equalizes air
pressure on both sides of the tympanic membrane.
8. The organ of Corti is located in which structure?
A. Semicircular canals
B. Cochlea
C. Vestibule
D. Middle ear
Answer: B
Rationale: The organ of Corti is the sensory organ of hearing located within the cochlea of the inner
ear.
9. What type of hearing loss results from damage to the inner ear or auditory nerve?
A. Conductive
B. Sensorineural
C. Mixed
D. Mechanical
Answer: B
Rationale: Sensorineural hearing loss results from damage to the hair cells in the cochlea or the
auditory nerve -13.
10. Conductive hearing loss is caused by problems in which part(s) of the ear?
A. Inner ear only
,B. Outer or middle ear
C. Auditory nerve
D. Cochlea
Answer: B
Rationale: Conductive hearing loss occurs when sound is not efficiently conducted through the outer
or middle ear to the inner ear.
11. Which of the following is a symptom commonly associated with sensorineural hearing loss?
A. Ear fullness
B. Tinnitus
C. Normal speech discrimination in noise
D. Improved hearing in noise
Answer: B
Rationale: Tinnitus, difficulty understanding speech in noise, and reduced speech discrimination are
typical symptoms of sensorineural hearing loss. Ear fullness is more commonly associated with
conductive or middle-ear pathology -18.
12. What does the term "recruitment" refer to in audiological testing?
A. The process of hiring new staff
B. Abnormally rapid growth of loudness perception
C. The ability to hear soft sounds but not loud ones
D. A type of tympanometry result
Answer: B
Rationale: Recruitment is an abnormal phenomenon, typically in sensorineural hearing loss, where a
small increase in stimulus intensity above threshold produces an abnormally large increase in
perceived loudness -16.
13. What is presbycusis?
A. Hearing loss caused by noise exposure
B. Age-related hearing loss
C. Hearing loss caused by ototoxic drugs
D. Congenital hearing loss
Answer: B
Rationale: Presbycusis is age-related hearing loss, typically characterized by bilateral, high-frequency
sensorineural loss.
14. The stapedius muscle contracts in response to:
A. Soft sounds
B. Loud sounds
C. Low-frequency sounds only
D. Bone conduction stimulation only
Answer: B
Rationale: The stapedius muscle contracts in response to loud sounds as part of the acoustic reflex,
stiffening the ossicular chain to reduce sound transmission.
15. When both stapedius muscles contract even though only one ear is stimulated, this is called:
A. Ipsilateral reflex
, B. Contralateral reflex
C. Consensual reflex
D. Bilateral reflex
Answer: C
Rationale: The consensual reflex occurs when both stapedius muscles contract even though only one
ear is stimulated -3.
16. What is the primary function of the pinna?
A. To amplify high frequencies
B. To collect sound and assist in localization
C. To produce cerumen
D. To equalize pressure
Answer: B
Rationale: The pinna collects sound waves and assists with sound localization, particularly for
determining the elevation of sound sources.
17. Which frequency range is most affected by a head cold?
A. High frequencies (2000–8000 Hz)
B. Low frequencies (250–500 Hz)
C. Ultra-high frequencies (above 8000 Hz)
D. All frequencies equally
Answer: B
Rationale: A head cold often causes middle ear effusion or Eustachian tube dysfunction, which
primarily affects low-frequency hearing (250–500 Hz) -3.
18. What is the significance of the air-bone gap?
A. It indicates sensorineural hearing loss
B. It indicates a difference between air and bone conduction thresholds
C. It measures speech discrimination
D. It measures loudness discomfort levels
Answer: B
Rationale: An air-bone gap is the difference between air conduction and bone conduction
thresholds, indicating a conductive component to hearing loss.
19. A significant air-bone gap is defined as a difference of how many decibels at 2 or more
consecutive frequencies?
A. 5 dB
B. 10 dB
C. 15 dB
D. 20 dB
Answer: C
Rationale: A significant air-bone gap is a difference of 15 decibels or more between air conduction
and bone conduction thresholds at 2 or more succeeding octave frequencies from 500 Hz through
4000 Hz -1-8.
20. The semicircular canals are responsible for:
A. Hearing
