In sensorineural hearing loss, weber’s test is lateralized to
**Question:** In sensorineural hearing loss, weber's test is lateralized to
A. right side
B. left side
C. midline
D. mastoid process
**Correct Answer:** C. midline
**Core Concept:** Sensorineural hearing loss (SNHL) is a type of hearing impairment caused by damage to the sensory hair cells or auditory nerve in the inner ear. The Weber's test is a clinical test used to localize the origin of hearing loss and to differentiate between conductive and sensorineural hearing loss.
**Why the Correct Answer is Right:** In a normal subject, the sound source (e.g., a tuning fork) placed on the midline (C) of the body produces a symmetric response because the sound waves travel through both the outer ear, middle ear, and inner ear, resulting in equal perception of sound on both sides. However, in sensorineural hearing loss, the perception of sound is affected due to damage to the inner ear structures.
**Why Each Wrong Option is Incorrect:**
A. Right side and B. Left side options are incorrect because weber's test is unable to differentiate between the right and left ear origin of hearing loss due to its symmetric response in a normal subject.
D. Mastoid process (D) is not the correct answer because the Weber's test localizes the hearing loss, not the mastoid process. The mastoid process is a bony prominence behind the pinna, and its location does not change the result of the Weber's test.
**Why Each Wrong Option is Incorrect:**
A. Right side and B. Left side options are incorrect because weber's test is unable to differentiate between the right and left ear origin of hearing loss due to its symmetric response in a normal subject.
D. Mastoid process (D) is not the correct answer because the Weber's test localizes the hearing loss, not the mastoid process. The mastoid process is a bony prominence behind the pinna, and its location does not change the result of the Weber's test.
**Clinical Pearl:** While performing the Weber's test, you should ensure that the sound source is placed on the midline of the body to obtain a symmetric response in a normal subject. In case of sensorineural hearing loss, the response will be asymmetric, indicating the side of the lesion (hearing loss). This is because the test localizes the hearing loss, not the mastoid process.