Overview of Tuning Fork Tests- Rinne and Weber Tests

The Rinne and Weber are exams that test the hearing impairment of a person. They help in determining the type of unilateral hearing loss such as sensorineural or conductive hearing loss. By determining the type hearing loss helps the doctor to start a treatment plan related to the hearing impairment. These tests require a full examination of the cranial nerves or the ear.

The Rinne and Weber tests are usually performed together.  Therefore, combining the result of each other test together helps in finding out the nature and location of the certain hearing impairment.

A sensorineural hearing occurs from the gradual damage to the hair cells in the cochlea. Hair loss damage can occur because of many reasons such as –

  • Excessive noise
  • Exposure to diseases such as Meniere’s disease, meningitis, mumps and multiple sclerosis.
  • Usage of certain drugs such as quinine, aspirin, cisplatin or some antibiotics like gentamicin or streptomycin.
  • It also can be inherited or can occur in case the mother has had rubella during the pregnancy period.

A Conductive hearing loss results from a difficulty in conducting sound waves through the outer ear, eardrum or ossicles( middle ear). It can also occur in combination with a sensorineural hearing loss(mixed hearing loss). There are many causes of conductive hearing loss such as-

  • Fluid accumulation in the middle ear,
  • Malfunction of the ear canal, outer canal, or middle ear
  • Ear canal infection
  • Otosclerosis
  • Allergies
  • Perforated eardrum
  • Otitis media or Ear infection

Benefits of Rinne and Weber tests

The Rinne and Weber Tests are always executed together. Between Rinne and Weber, Rinne test is performed first. These tests are the first test which helps all the hearing impaired people with their hearing difficulty.

They help in determining the difference between sensorineural and conductive hearing loss. Therefore, these tests guide the doctor in further examination and investigation of the treatment process.

 What is Rinne Test?

Rinne test is essentially used for examining unilateral hearing or hearing loss in one ear. It helps in making a comparison between sounds transferred by air conduction to those transferred by bone conduction through the mastoid.

Air conduction is the conduction of the sound waves in the inner ear of the person through the eardrum and ear canal. Whereas in bone conduction hearing the nervous system linked to ear pick up vibrations. This test helps the doctor in finding the suitable treatment plan according to the hearing difficulty in the patient.

How a Doctor performs a Rinne Test?

  • Doctors ideally use 512 Hz frequency tuning fork. They struck the fork against the knee or the elbow of the patient. A proper strike is made at the intersection of the lower 2/3 and upper 1/3 of the fork. This intersection area is the maximum vibratory area of the fork.
  • As the tuning fork begins to start vibrating then the doctor places the fork at the mastoid bone behind the ear.
  • The patient is asked to signal the doctor as soon as he stops hearing any kind of sound. And then the vibrating fork is placed close to the external auditory canal. The tuning fork is held in a way that the vibratory prongs or point vibrate side by side to the acoustic axis.
  • The patient again signals the doctor in case of any hindrance in sound. Then the doctor records the time duration of each sound.

What is a Weber Test?

A  Weber Test is very useful for those people who have hearing different in both the ears. This test does not confirm normal hearing of a person as the sound sensitivity is not measured in a quantitative manner. Weber test is named after Ernst Heinrich Weber.

There are two motives behind using a Weber test-

  • For finding the conductive or sensorineural hearing loss.
  • In case the hearing loss is sensorineural then checking the functions of ear’s cochlea.

How a Doctor Perform a Weber test?

A professional can do Weber Test in three ways –

  • Tunning fork tests
  • Audiometry
  • Clinical voice test

Tunning fork tests

The professionals in this Weber Test uses a tuning fork of frequency 254Hz, 512 Hz, 1024 Hz. Usually, a frequency less than 254 Hz is not used as they are better felt than heard by a patient. Whereas the frequency greater than 1024 Hz is not used as they are extremely poor.

Conditions for ideal tuning fork

  • Professional uses tunning fork made from good alloy.
  • It is good to use a tuning fork which vibrates at a certain frequency.
  • The vibration of the tuning fork needs to have the capacity of at least one minute.
  • Tunning forks are not used which produce any kind of overtones.

How to use a tuning fork?

Struck the tuning fork against a firm surface which can be the elbow of the examiner or any rubber pad. Then struck the tuning fork at an intersection of lower 2/3 and upper 1/3 of the fork. A vibrating fork of 512 Hz frequency is set in the center of the skull. And the person is then asked regarding sound that is heard more at the place where it is produced which is the middle of the skull or only in one specific ear.

A good examiner always tries to hold the vibrating fork parallel to the acoustic axis of the ear of the patient.

How does a person prepare for Rinne and Weber Tests?

A person needs to be in a completely quiet room for Rinne and Weber tests. Always, try to wash your hands before the test. No other required is necessary for these test as they are very simple to perform.

Test results for Rinne and Weber tests

The Rinne and Weber tests are not associated with any kind of risk or pain. It is a very simple test which determines the cause and type of hearing impairment.

Rinne Test results

  • Normal hearing – Air conduction will be more than bone conduction. Therefore, the person is able to hear the tuning fork sound close to the outer ear(pinna). However, the person will not hear the sound afterward when held against mastoid.
  • Abnormal Hearing – A person with hearing difficulty will not hear the tuning fork sound after it changed from mastoid to pinna. Therefore, the bone conduction is more than air conduction, up to twice more than air conduction. This is also called negative Rinne. In both the ears, this test is performed. This result is shown in the Conductive hearing loss. 

In case of sensorineural hearing loss, a person will hear the tuning fork by air conduction. However, after that sound, an individual will not hear any further sound through bone conduction. This pattern is similar to normal hearing. Therefore, air conduction will be more than bone conduction. However, it will not be twice. It is called Rinne’s false positive.

Weber’s Test Results

In a Normal hearing, a person hears the sound of tuning fork in both the ear equally. An individual with a one-sided conductive deafness(unilateral) will hear the sound of tuning fork louder in the affected ear. As the conduction difficulty covers the surrounding noise of the room.

Whereas in the sensorineural deafness, the normal inner ear picks the sound up through the skull bone. And the sound will be heard louder than in the normal ear.

Limitations of Rinne and Weber test

In some cases of unilateral or total sensorineural hearing loss, the Rinne test is not dependable in distinguishing conductive and sensorineural hearing impairment. These cases result in false negative, therefore, bone conduction will be more than air conduction.

In some cases, Weber test will show signs of lateralization, indicating some kind of pathology. Therefore, in case of abnormal results audiometry testing is considered.

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