It is seen in patients having conductive deafness. It is seen in normal persons or patients having sensorineural deafness. Alternatively, the patient may be asked to compare the loudness of sound heard through air and bone conduction. If he still hears the sound, it means air conduction is more than bone conduction. When the subject indicates that he can’t hear the sound anymore, the tuning fork is brought 25 mm (2.5 cm) in front of external auditory canal, parallel to the acoustic axis. Rinne’s test.The base of a vibrating tuning fork is kept on the mastoid bone of the patient.The clinically useful tuning fork tests include: Thus, BC is a measure of the cochlear function only. The cochlea is stimulated directly by vibrations conducted through the skull bones. To test bone conduction (BC), the footplate of the vibrating tuning fork is placed firmly on the mastoid bone. Normally, hearing through air conduction is louder and heard twice as long as through the bone conduction route.

Thus, by the air conduction test, the function of both the conducting mechanism and the cochlea are tested. The sound waves are transmitted through the tympanic membrane, middle ear and ossicles to the inner ear. To test air conduction (AC), a vibrating fork is placed vertically in line with the meatus, about 2 cm away from the opening of the external auditory canal. The practitioner stabilizes the patient’s head with one hand.Explain to the patient that he should raise his finger when he no longer hears the sound.To produce a pure tone, strike the prong at a point 1/3rd of its length from its free end (this will minimize overtones and produce accurate results.).To activate tuning fork, strike it gently against the examiner’s elbow, the heel of the hand or the rubber heel of the shoe.Tuning fork tests Tuning fork tests Tuning fork tests Tuning fork tests Shorter frequency forks are not preferred as they give a sense of bone vibration, while higher frequency forks are not preferred due to their shorter decay time. In clinical practice, tuning fork of 512 Hz is considered ideal (Optimum decay time and produce minimal overtones). Selection of Tuning fork: Tuning forks of varying frequencies such as 128, 256, 512, 1024, 20 hertz are available in the market.

Normal rinne test