Blocking of the eustachian tube leads to decreased pressure in the middle ear relative to the external ear, and this causes decreased motion of both the ossicles and the tympanic membrane. Acute or Serous otitis media
Chronic suppurative otitis media (CSOM)
Perforated eardrum
Tympanosclerosis or scarring of the eardrum
Cholesteatoma
Eustachian Tube Dysfunction, inflammation or mass within the nasal cavity, middle ear, or eustachian tube itself
Otosclerosis, abnormal growth of bone in or near the middle ear
Middle ear tumour
Ossicular discontinuity as a consequence of infection or temporal bone trauma
Congenital malformation of the ossicles. This can be an isolated phenomenon or can occur as part of a syndrome where development of the 1st and 2nd branchial arches is seen such as in Goldenhar syndrome, Treacher Collins syndrome, branchio-oto-renal syndrome etc. Barotrauma unequal air pressures in the external and middle ear. This can temporarily occur, for example, by the environmental pressure changes as when shifting altitude, or inside a train going into a tunnel. It is managed by any of various methods of ear clearing manoeuvres to equalize the pressures, like swallowing, yawning, or the Valsalva manoeuvre. More severe barotrauma can lead to middle ear fluid or even permanent sensorineural hearing loss. Inner ear
Third window effect caused by:

Superior canal dehiscence – which may require surgical correction. Enlarged vestibular aqueduct
Labyrinthine fistula

Presentation
Conductive hearing loss makes all sounds seem faint or muffled. The hearing loss is usually worse in lower frequencies. Congenital conductive hearing loss is identified through newborn hearing screening or may be identified because the baby has microtia or other facial abnormalities.
Causes
It is important to distinguish association and causation. The vast majority of trigger digits are idiopathic, meaning there is no known cause. Some speculate that repetitive forceful use of a digit leads to narrowing of the fibrous digital sheath in which it runs, but there is little scientific data to support this theory. The relationship of trigger finger to work activities is debatable and there are arguments for and against a relationship to hand use with no experimental evidence supporting a relationship. Diagnosis
Diagnosis is made on interview and physical examination. More than one finger may be affected at a time. It is most common in the thumb and ring finger. The triggering more often occurs while gripping an object firmly or during sleep when the palm of the subject’s hand remains closed for an extended period of time. Upon waking, the affected person may have to force the triggered fingers open with their other hand. In some, this can be a daily occurrence. Treatment
Corticosteroid injections can cure trigger digits. Treatment consists of injection of a corticosteroid such as methylprednisolone often combined with a local anesthetic (lidocaine) at the A1 pulley in the palm. The infiltration of the affected site is straightforward using standard anatomic landmarks. There is evidence that the steroid does not need to enter the sheath. The role of sonographic guidance is therefore debatable. Injection of the tendon sheath with a corticosteroid is effective over weeks to months in more than half of people.