3. Conductive hearing loss: there is obstruction of external auditory canal or disease of middle ear. Sensorineural hearing loss: disease affecting cochlea or cochlear nerve. Mixed type

4. Objectives: To examine and compare air and bone conduction of the subject. instruments :Vibrating tuning fork (512 Hz).

5. Rinne's test Base of vibrating tuning fork placed on mastoid process until subject no longer hears sound then the vibrating top is placed one inch from the external ear canal (air).

6. Normally : The subject hears vibrating of the tuning fork in air after bone conduction is over. This is called Rinne's positive (i.e air conduction is better than bone conduction). In conductive hearing loss: (one ear) : patient does not hear vibration in air after bone conduction is over this is called Rinne's negative In sensorineural hearing loss : (one ear), patient hears vibration in air after bone conduction is over.i.e Rinne's positive

7. Weber's test The base of vibrating tuning fork is placed on the patient's forehead or the nasal root exactly in the midline.

8. Normally : Subject hears equally on both sides In conductive hearing loss (one ear) : The sound of the vibrating tuning fork is louder in diseased ear because masking effect of environmental noise is absent in diseased side. In sensorineural hearing loss (one ear): sound louder in normal ear. sensirineural Normal conductive

9. Schwabach's test In this test we compare bone conduction of the patient with that of a normal subject. Normally: bone conduction is the same for examiner and patient In conductive hearing loss: bone conduction is better than examiner. In sensorineural hearing loss: bone conduction is less than examiner.

10. Rinne's testWeber's testSchwabach's test Normallyair conduction is better than bone conduction hears equally on both sides bone conduction is the same for examiner and patient Conductive hearing loss patient does not hear vibration in air after bone conduction is over Hears the sound louder in diseased ear bone conduction is better than examiner Partial sensorineural hearing loss air conduction is better than bone conduction Hears the sound louder in normal ear bone conduction of patient is less than examiner Complete sensorineural deafness Hears no sound in both air and bone Hears the sound louder in normal ear bone conduction of patient is less than examiner

11. Audiometer instrument to assess hearing in person with hearing problem. pure tones at various frequencies are generated,and their levels are increased and decreased until threshold are found.

12. Objective of the test 1-Shows whether hearing is normal or not 2-If the hearing is abnormal,it shows the severity of hearing loss 3-Also it shows type of hearing loss whether conductive or sensorineural or mixed type.

13. How to do the test In isolated room first we measure air conduction by using ear phones,we deliver sounds for each frequency we change the intensity till we get the lowest intensity which the subject hear. The same is done for bone conduction.but we used bone vibrator instead of the ear phones. So the graphic representation between frequency and intensity called audiogram