Conductive hearing loss may also result from middle ear inflammation causing fluid build-up in the normally air-filled space, such as by otitis media. Tympanoplasty is the general name of the operation to repair the middle ears eardrum and ossicles. Grafts from muscle fascia are ordinarily used to rebuild an intact eardrum. Sometimes artificial ear bones are placed to substitute for damaged ones, or a disrupted ossicular chain is rebuilt in order to conduct sound effectively. Hearing aids or cochlear implants may be used if the hearing loss is severe or prolonged. Hearing aids work by amplifying the sound of the local environment and are best suited to conductive hearing loss. Cochlear implants transmit the sound that is heard as if it were a nervous signal, bypassing the cochlea. Active middle ear implants send sound vibrations to the ossicles in the middle ear, bypassing any non-functioning parts of the outer and middle ear. Congenital abnormalities
Anomalies and malformations of the pinna are common. These anomalies include chromosome syndromes such as ring 18. Children may also present cases of abnormal ear canals and low ear implantation. In rare cases no pinna is formed (atresia), or is extremely small (microtia). Small pinnae can develop when the auricular hillocks do not develop properly. The ear canal can fail to develop if it does not channelise properly or if there is an obstruction.
Thromboembolism (blood clots)
Embolism (foreign bodies in the circulation, e.g. amniotic fluid embolism)

Trauma
Traumatic injury to an extremity may produce partial or total occlusion of a vessel from compression, shearing, or laceration. Acute arterial occlusion may develop as a result of arterial dissection in the carotid artery or aorta or as a result of iatrogenic arterial injury (e.g., after angiography). Other
An inadequate flow of blood to a part of the body may be caused by any of the following:

Thoracic outlet syndrome (compression of the brachial plexus)
Atherosclerosis (lipid-laden plaques obstructing the lumen of arteries)
Hypoglycemia (lower than normal level of glucose)
Tachycardia (abnormally rapid beating of the heart)
Radiotherapy
Hypotension (low blood pressure, e.g. in septic shock, heart failure)
Outside compression of a blood vessel, e.g. by a tumor or in the case of superior mesenteric artery syndrome
Sickle cell disease (abnormally shaped red blood cells)
Induced g-forces which restrict the blood flow and force the blood to the extremities of the body, as in acrobatics and military flying
Localized extreme cold, such as by frostbite or improper cold compression therapy
Tourniquet application
An increased level of glutamate receptor stimulation 
Arteriovenous malformations and peripheral artery occlusive disease
rupture of significant blood vessels supplying a tissue or organ. Anemia vasoconstricts the periphery so that red blood cells can work internally on vital organs such as the heart, brain, etc., thus causing lack of oxygen to the periphery. Premature discontinuation of any oral anticoagulant.