NBC-HIS National Competency Exam Test
Bank 2026/2027 | 120 Practice Questions with
Answers & Clinical Case Studies for Hearing
Instrument Specialists
Description:
Pass the NBC-HIS exam in 2026/2027 with this comprehensive test bank featuring 120
practice questions, detailed answer explanations, and real-world clinical case studies. Updated
for current exam standards.
Download now and start your guaranteed prep today!
, NBC-HIS Prep 2026: 120 Exam Questions & Answers
SECTION 1: AUDIOLOGY & HEARING ASSESSMENT
Question 1
Which of the following is the most common cause of hearing loss presenting as a bilateral notch
at 4000 Hz?
A. Presbycusis
B. Ototoxicity
C. Acoustic Trauma
D. Meniere's Disease
Answer: C. Acoustic Trauma
Explanation: Acoustic trauma typically presents as a bilateral sensorineural hearing loss with a
characteristic notch at 4000 Hz. This frequency is particularly vulnerable to noise-induced
damage due to the resonance characteristics of the external auditory canal and the mechanical
properties of the basilar membrane. Prolonged or acute exposure to high-intensity sounds
damages the outer hair cells in the cochlea, with the basal turn responsible for high frequencies
being most susceptible. This pattern is distinct from presbycusis, which typically shows a
gradual high-frequency sloping loss, and from ototoxicity, which often affects higher frequencies
above 8000 Hz initially.
Question 2
A 32-year-old female patient presents with concerns that her hearing has declined since the birth
of her first child. Audiometric testing reveals a bilateral conductive hearing loss with an air-bone
gap. Which condition is most likely responsible?
A. Otosclerosis
B. Otitis Media with Effusion
C. Perforated Tympanic Membrane
D. Cholesteatoma
Answer: A. Otosclerosis
,Explanation: Otosclerosis is characterized by abnormal bone remodeling in the otic capsule,
most commonly affecting the stapes footplate. It is more prevalent in women and often presents
or worsens during pregnancy, likely due to hormonal changes that accelerate the disease process.
Audiometric findings typically include a bilateral conductive hearing loss with a Carhart notch at
2000 Hz on bone conduction. Tympanometry typically shows a Type As pattern, indicating
reduced compliance due to stapes fixation.
Question 3
A unilateral large dip at 6000 Hz accompanied by positive tone decay in the affected ear is most
indicative of which condition?
A. Noise-induced hearing loss
B. Otosclerosis
C. Possible retrocochlear pathology
D. Meniere's Disease
Answer: C. Possible retrocochlear pathology
Explanation: A unilateral dip at 6000 Hz with positive tone decay is a red flag for retrocochlear
pathology, most notably acoustic neuroma. Tone decay testing measures auditory adaptation; a
positive result suggests neural involvement rather than cochlear dysfunction. Retrocochlear
lesions typically affect the auditory nerve or brainstem pathways, producing asymmetric hearing
loss, poor speech discrimination out of proportion to pure-tone loss, and abnormal auditory
brainstem response findings. This pattern should prompt immediate referral for MRI or other
imaging studies to rule out space-occupying lesions.
Question 4
A patient reports that their hearing aids functioned properly until they were cleaned by the
patient, after which the devices became weak and began feeding back. What is the most likely
cause?
A. Batteries were inserted incorrectly
B. Receiver tubing has been pushed in too far
C. Microphone ports are blocked
D. The volume control was inadvertently turned down
, Answer: B. Receiver tubing has been pushed in too far
Explanation: When receiver tubing is pushed too far into the ear canal or the earmold, it can
occlude the sound bore, reducing the effective output of the hearing aid while simultaneously
creating an acoustic leak that results in feedback. This is a common issue when patients attempt
to clean their own devices without proper training. The tubing should extend just past the second
bend of the ear canal for optimal acoustic performance. When inserted too deeply, the tubing
may also cause discomfort and alter the frequency response of the instrument.
Question 5
How does an osteoma typically present during otoscopic examination?
A. As a red, inflamed mass in the middle ear
B. As a bony growth in the external auditory canal
C. As a perforation of the tympanic membrane
D. As a retracted tympanic membrane
Answer: B. As a bony growth in the external auditory canal
Explanation: An osteoma is a benign, slow-growing bony tumor that typically arises in the
external auditory canal. It presents as a smooth, hard, unilateral or bilateral mass that is covered
with normal skin. Osteomas are more common in individuals with a history of cold water
exposure and are usually asymptomatic unless they become large enough to cause conductive
hearing loss or cerumen impaction. They are distinct from exostoses, which are multiple,
bilateral bony growths also associated with cold water exposure.
Question 6
Which speech recognition test can be effectively administered in a sound field environment for
validation purposes?
A. CID W-22
B. Northwestern University Auditory Test No. 6 (NU-6)
C. Synthetic Sentence Identification (SSI)
D. Speech Perception in Noise (SPIN) Test
Answer: B. Northwestern University Auditory Test No. 6 (NU-6)
Bank 2026/2027 | 120 Practice Questions with
Answers & Clinical Case Studies for Hearing
Instrument Specialists
Description:
Pass the NBC-HIS exam in 2026/2027 with this comprehensive test bank featuring 120
practice questions, detailed answer explanations, and real-world clinical case studies. Updated
for current exam standards.
Download now and start your guaranteed prep today!
, NBC-HIS Prep 2026: 120 Exam Questions & Answers
SECTION 1: AUDIOLOGY & HEARING ASSESSMENT
Question 1
Which of the following is the most common cause of hearing loss presenting as a bilateral notch
at 4000 Hz?
A. Presbycusis
B. Ototoxicity
C. Acoustic Trauma
D. Meniere's Disease
Answer: C. Acoustic Trauma
Explanation: Acoustic trauma typically presents as a bilateral sensorineural hearing loss with a
characteristic notch at 4000 Hz. This frequency is particularly vulnerable to noise-induced
damage due to the resonance characteristics of the external auditory canal and the mechanical
properties of the basilar membrane. Prolonged or acute exposure to high-intensity sounds
damages the outer hair cells in the cochlea, with the basal turn responsible for high frequencies
being most susceptible. This pattern is distinct from presbycusis, which typically shows a
gradual high-frequency sloping loss, and from ototoxicity, which often affects higher frequencies
above 8000 Hz initially.
Question 2
A 32-year-old female patient presents with concerns that her hearing has declined since the birth
of her first child. Audiometric testing reveals a bilateral conductive hearing loss with an air-bone
gap. Which condition is most likely responsible?
A. Otosclerosis
B. Otitis Media with Effusion
C. Perforated Tympanic Membrane
D. Cholesteatoma
Answer: A. Otosclerosis
,Explanation: Otosclerosis is characterized by abnormal bone remodeling in the otic capsule,
most commonly affecting the stapes footplate. It is more prevalent in women and often presents
or worsens during pregnancy, likely due to hormonal changes that accelerate the disease process.
Audiometric findings typically include a bilateral conductive hearing loss with a Carhart notch at
2000 Hz on bone conduction. Tympanometry typically shows a Type As pattern, indicating
reduced compliance due to stapes fixation.
Question 3
A unilateral large dip at 6000 Hz accompanied by positive tone decay in the affected ear is most
indicative of which condition?
A. Noise-induced hearing loss
B. Otosclerosis
C. Possible retrocochlear pathology
D. Meniere's Disease
Answer: C. Possible retrocochlear pathology
Explanation: A unilateral dip at 6000 Hz with positive tone decay is a red flag for retrocochlear
pathology, most notably acoustic neuroma. Tone decay testing measures auditory adaptation; a
positive result suggests neural involvement rather than cochlear dysfunction. Retrocochlear
lesions typically affect the auditory nerve or brainstem pathways, producing asymmetric hearing
loss, poor speech discrimination out of proportion to pure-tone loss, and abnormal auditory
brainstem response findings. This pattern should prompt immediate referral for MRI or other
imaging studies to rule out space-occupying lesions.
Question 4
A patient reports that their hearing aids functioned properly until they were cleaned by the
patient, after which the devices became weak and began feeding back. What is the most likely
cause?
A. Batteries were inserted incorrectly
B. Receiver tubing has been pushed in too far
C. Microphone ports are blocked
D. The volume control was inadvertently turned down
, Answer: B. Receiver tubing has been pushed in too far
Explanation: When receiver tubing is pushed too far into the ear canal or the earmold, it can
occlude the sound bore, reducing the effective output of the hearing aid while simultaneously
creating an acoustic leak that results in feedback. This is a common issue when patients attempt
to clean their own devices without proper training. The tubing should extend just past the second
bend of the ear canal for optimal acoustic performance. When inserted too deeply, the tubing
may also cause discomfort and alter the frequency response of the instrument.
Question 5
How does an osteoma typically present during otoscopic examination?
A. As a red, inflamed mass in the middle ear
B. As a bony growth in the external auditory canal
C. As a perforation of the tympanic membrane
D. As a retracted tympanic membrane
Answer: B. As a bony growth in the external auditory canal
Explanation: An osteoma is a benign, slow-growing bony tumor that typically arises in the
external auditory canal. It presents as a smooth, hard, unilateral or bilateral mass that is covered
with normal skin. Osteomas are more common in individuals with a history of cold water
exposure and are usually asymptomatic unless they become large enough to cause conductive
hearing loss or cerumen impaction. They are distinct from exostoses, which are multiple,
bilateral bony growths also associated with cold water exposure.
Question 6
Which speech recognition test can be effectively administered in a sound field environment for
validation purposes?
A. CID W-22
B. Northwestern University Auditory Test No. 6 (NU-6)
C. Synthetic Sentence Identification (SSI)
D. Speech Perception in Noise (SPIN) Test
Answer: B. Northwestern University Auditory Test No. 6 (NU-6)
