Ear, Otoscopy and Hearing OSCE Examination

Contents

1. Introduction
2. General Inspection
3. Inspection of the Outer Ear
4. Otoscopy
5. Gross Hearing Assessment
6. Tuning Fork Tests – Weber’s Test
7. Tuning Fork Tests – Rinne’s Test
8. Completing the Examination
9. Quiz

Introduction

Wash your hands and put on personal protective equipment if appropriate.

Introduce yourself to the patient and ensure to mention your grade e.g. 3rd year medical student/junior doctor/consultant.

Confirm the patient’s details taking 3 points of identification usually; Full name, Date of birth and NHS/Hospital number.

Obtain consent for the examination ensuring to explain what the examination will entail, including that you will need to look inside both ears and carry out some simple hearing tests.

Position the patient sitting upright on a chair, with you able to access both ears from the side.

Ask whether the patient has any ear pain or discharge before you begin, as the examination of a painful ear should be performed gently and last.

Gather your equipment before you start so that the examination flows smoothly: an otoscope with a working light, a selection of disposable specula in different sizes, a 512 Hz tuning fork for the Rinne and Weber tests, and alcohol gel for hand hygiene. Check the otoscope light works and is bright before you begin.

General Inspection

Begin by stepping back and observing the patient and their surroundings. Note whether the patient appears comfortable or in distress, and whether they are turning a particular ear towards you or watching your lips closely, which can be subtle clues to hearing impairment.

Look for any hearing aids, which immediately suggest a degree of established hearing loss, or a cochlear implant (a processor worn behind the ear with a magnetic disc on the scalp), which indicates severe sensorineural loss.

Inspect for an obvious facial nerve palsy, as the facial nerve (cranial nerve VII) runs through the temporal bone in close relationship to the middle ear and can be affected by middle ear disease, cholesteatoma, or surgery. Look at the bedside for any tissues, cotton buds, or evidence of discharge.

Image - A right lower motor neurone facial nerve palsy, with loss of the forehead creases and drooping of the corner of the mouth. The facial nerve’s course through the temporal bone means middle ear disease and ear surgery can produce this picture

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Inspection of the Outer Ear

Inspect each pinna in turn, comparing both sides. Look at the front and behind the ear, and remember to lift the pinna forwards to inspect the post-auricular sulcus and the area behind the ear.

Note the shape and size of each pinna. A deformity may be congenital, such as a small or absent pinna (microtia or anotia) or low-set ears seen in some genetic syndromes, or acquired, such as the lumpy cauliflower ear that follows repeated trauma and an untreated auricular haematoma.

Look for scars. A post-auricular scar may indicate previous mastoid surgery (mastoidectomy), while an endaural scar at the front of the ear canal suggests previous middle ear surgery. These point towards chronic ear disease such as cholesteatoma.

Inspect the skin for signs of inflammation, swelling or discharge. A red, swollen and tender pinna and canal with discharge suggests otitis externa (infection of the external ear canal). If the pinna itself is hot, red and exquisitely tender but the lobule (which contains no cartilage) is spared, consider perichondritis, an infection of the cartilage that can lead to permanent deformity if untreated.

Feel behind the ear for a tender, boggy swelling that pushes the pinna forwards and outwards with loss of the post-auricular sulcus. This is the classic appearance of mastoiditis, a serious complication of middle ear infection in which infection spreads into the air cells of the mastoid bone, and it requires urgent assessment.

Also note any obvious pre-auricular skin lesions (basal or squamous cell carcinomas are common on the sun-exposed pinna) and a pre-auricular sinus, a small congenital pit in front of the ear that can become infected.

Palpate the regional lymph nodes that drain the ear – the pre-auricular and post-auricular nodes and the upper cervical chain. Enlarged, tender nodes accompany local infection such as otitis externa, while a hard, fixed node should raise concern about malignancy of the pinna or canal.

Finally, gently move the pinna and press on the tragus. Pain on moving the pinna or pushing the tragus (a positive tragal sign) is typical of otitis externa, whereas pain on this manoeuvre is usually absent in otitis media, where the tenderness is felt deeper. This simple test helps distinguish outer ear from middle ear disease before you reach for the otoscope.

Otoscopy

Otoscopy allows you to inspect the external auditory meatus and the tympanic membrane (eardrum). Examine the normal (asymptomatic) ear first so that you do not transfer infection and so that you have a comparison for the affected side.

Select the largest speculum that comfortably fits the canal, as this gives the best view and the most light. Turn the otoscope light on and hold it like a pen in your right hand for the patient’s right ear and your left hand for the left ear.

To straighten the naturally S-shaped ear canal in an adult, gently pull the pinna upwards and backwards. (In an infant or young child the canal is straightened by pulling the pinna downwards and backwards instead.) Brace the hand holding the otoscope against the patient’s cheek so that if they move suddenly the instrument moves with them, avoiding injury to the canal.

Advance the speculum under direct vision. Inspect the canal walls for wax, debris, discharge, swelling or foreign bodies. Wax (cerumen) is normal and protective but excessive wax may obscure the view and cause conductive hearing loss. Pus or debris in the canal suggests otitis externa.

Now examine the tympanic membrane. A normal eardrum is pearly grey, translucent and slightly concave. You should identify the handle of the malleus running downwards and backwards, the pars tensa below it, and a cone of light (light reflex) radiating anteroinferiorly from the tip of the malleus – classically at the 5 o’clock position in the right ear and the 7 o’clock position in the left ear. Above the malleus lies the smaller pars flaccida.

Image - A normal left tympanic membrane. It is pearly grey and translucent, with the handle of the malleus visible and a cone of light radiating anteroinferiorly

Creative commons source by Michael Hawke MD [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]

Look for the following abnormalities, each of which reflects a specific pathology:

• A red, bulging eardrum with loss of the normal landmarks and light reflex suggests acute otitis media, where pus under pressure pushes the drum outwards.
• A dull, retracted drum with a visible fluid level or bubbles behind it suggests otitis media with effusion (‘glue ear’), caused by Eustachian tube dysfunction and negative middle ear pressure. This is a common cause of conductive hearing loss in children.
• A perforation appears as a defect in the drum. It may follow infection or trauma, and a persistent perforation causes conductive hearing loss.
• A retraction pocket or whitish keratin debris, classically in the attic (pars flaccida), raises suspicion of a cholesteatoma – an expanding collection of keratinising squamous epithelium that erodes bone and can cause serious complications.
• Grommets (tympanostomy tubes) may be seen as small ventilation tubes inserted through the drum to treat recurrent effusions.

Gross Hearing Assessment

A bedside hearing screen quickly tells you whether hearing is grossly intact and helps identify the worse ear. Test each ear separately, masking the non-test ear so that sound cannot reach the cochlea on that side: gently rub the tragus or occlude the canal. Reach round behind the patient’s head to do this rather than across their face, which is more comfortable and avoids obscuring their view of your lips for the test ear.

Position yourself about an arm’s length (60 cm) from the test ear, out of the patient’s line of sight so they cannot lip-read. Whisper a combination of numbers and letters (for example a two-digit number and a letter) and ask the patient to repeat it back. Use a different combination for each attempt so the patient cannot guess. If the patient repeats roughly two-thirds or more of the items correctly, hearing in that ear is broadly intact at that intensity.

If they cannot hear the whisper, repeat at a normal conversational volume, and then a loud voice, moving closer (around 15 cm) for the higher intensities. Each step up in volume and proximity corresponds to a worse threshold of hearing, so the louder and closer you have to go before the patient responds, the greater the loss. Inability to hear a whispered voice at arm’s length suggests a significant hearing loss in that ear and prompts more formal testing.

The gross test only tells you that hearing is reduced – it does not tell you why. To distinguish conductive from sensorineural loss you need the tuning fork tests.

Tuning Fork Tests – Weber’s Test

Tuning fork tests use a 512 Hz fork. This frequency is chosen because it gives the best balance between an audible tone and a long enough decay time – lower-frequency forks are felt as vibration more than heard, and higher-frequency forks decay too quickly.

To set the fork in motion, strike it against your knee or elbow (a soft surface), never a hard table, which produces unwanted overtones.

For Weber’s test, place the base of the vibrating fork in the midline of the forehead (or on the vertex). Ask the patient: “Where do you hear the sound – in the middle, the left ear or the right ear?”

• Normal: the sound is heard equally in the midline, in both ears.
• Conductive hearing loss: the sound localises to the affected (worse) ear. This is because the absence of competing background (air-conducted) sound in the blocked ear allows bone-conducted sound to be perceived more clearly on that side.
• Sensorineural hearing loss: the sound localises to the unaffected (better) ear, because the damaged cochlea on the affected side perceives the bone-conducted tone less well.

Weber’s test alone cannot tell you which ear is abnormal – it only tells you the sound has lateralised. It must always be interpreted together with Rinne’s test.

Tuning Fork Tests – Rinne’s Test

Rinne’s test compares air conduction (AC) with bone conduction (BC) in each ear. In a healthy ear the entire conducting apparatus (canal, drum and ossicles) amplifies sound, so air conduction is normally better than bone conduction.

Strike the fork and place its base firmly on the mastoid process behind the ear to test bone conduction. Steady the patient’s head with your other hand. Ask the patient to tell you when they can no longer hear the tone. As soon as they say so, move the still-vibrating prongs to sit just in front of the external auditory meatus (without touching it) to test air conduction, and ask whether they can now hear it again.

• Rinne’s positive (normal): air conduction is better than bone conduction (AC > BC), so the patient still hears the fork at the ear after it has faded at the mastoid. This is the normal result and is also seen in sensorineural hearing loss, where both AC and BC are reduced but their normal relationship is preserved.
• Rinne’s negative (abnormal): bone conduction is better than air conduction (BC > AC), so the patient does not hear the fork when it is moved to the ear. This indicates a conductive hearing loss in that ear, because the damaged conducting apparatus can no longer amplify air-conducted sound, while the cochlea still detects vibration delivered directly through bone.

Beware the false-negative Rinne: in a severe unilateral sensorineural loss, the bone-conducted tone applied to the ‘deaf’ mastoid may actually be heard by the opposite, healthy cochlea, mimicking a conductive picture. Combining Rinne with Weber, and ultimately with pure tone audiometry, resolves this.

Putting the two tests together gives you a quick way to characterise the loss, which is exactly what an examiner wants to hear you interpret out loud:

• Normal hearing: Weber central; Rinne positive (AC > BC) in both ears.
• Conductive loss (e.g. wax, effusion, perforation, otosclerosis): Weber lateralises to the affected ear; Rinne negative (BC > AC) in the affected ear.
• Sensorineural loss (e.g. presbycusis, noise damage, ototoxicity): Weber lateralises to the better ear; Rinne positive (AC > BC) in both ears.

If the results do not fit one of these patterns – for example a Rinne that appears negative in a profoundly deaf ear – suspect a false-negative from cross-hearing and rely on Weber and formal audiometry to clarify.

Completing the Examination

Thank the patient and wash your hands.

Summarise your findings, stating whether hearing appeared normal or reduced and, if reduced, whether the tuning fork tests suggest a conductive or sensorineural pattern and in which ear.

To complete the examination, suggest performing a full examination of the cranial nerves (particularly the facial nerve, given its course through the temporal bone) and an examination of the vestibular system if the patient reports dizziness or balance problems, including the Romberg and head impulse tests and assessment for nystagmus.

Suggest examining the nose and throat, as Eustachian tube dysfunction and nasopharyngeal pathology can cause middle ear disease, and performing tympanometry to assess middle ear function and pure tone audiometry to formally quantify and characterise any hearing loss.

Quiz

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