Stand at arm’s length behind the patient and block<unk>  in one ear by occluding the ear canal.  Whisper a phrase and ask the patient to repeat it.  Test both ears.
Tone-emitting otoscope: Designed to view the ear canal and TM while emitting three different screening levels at random intervals.
Place a vibrating tuning fork on the forehead, equidistant to both ears
If the patient hears the sound equally in both ears, normal<unk>  or symmetric<unk>  is suspected.
If sound is heard more in affected ear → consider conductive<unk>  in affected ear
If sound is heard more in unaffected ear → consider sensorineural<unk>  in affected ear
A vibrating turning fork is placed on the mastoid bone behind the ear. When the sound is no longer heard, the fork is held near the ear canal.
If the sound is still present or louder at the ear canal, normal<unk>  is suspected. (i.e. Air conduction is greater than bone conduction)
If no sound is heard near the ear canal but the sound was still heard on the mastoid bone, conductive<unk>  is suspected in that ear. (i.e. bone conduction > air conduction)
Hum test comparable to Weber test in diagnostic accuracy of new onset unilateral conductive<unk> 
Hum test is conducted by asking the patient to hum and tell you in which ear the humming sounds louder
In sensorineural<unk> , humming is louder in the unaffected ear
In conductive<unk> , humming is louder in the affected ear
In sensorineural<unk> , humming is louder in the unaffected ear
In conductive<unk> , humming is louder in the affected ear
To evaluate mobility of the TM.
Nonmobile = fluid in middle ear, mass in middle ear, stiff/sclerotic TM.
Hypermobile TM = ossicular chain disruption.
Movable TM only with negative pressure = blocked Eustachian tube.
Outside scope of ED evaluation
Performed by an audiologist in a soundproof environment.  Air and bone conduction are both tested.
Consideration for these tests should be based on history and physical
Blood glucose
CBC to evaluate for anemia or infection
Thyroid testing
Serologic testing for Syphilis, Sjögren’s syndrome
CT scan for unexplained conductive<unk> 
MRI for sensorineural<unk> 
ENT evaluation for presbycusis
Differentiate between conductive and sensorineural<unk>
Hearing loss
Sudden Sensorineural Hearing Loss 
Hydrocephalus
Infections: 
Failure to thrive 
Barotrauma
Failure to thrive
Penetrating trauma