Product liability lawsuits keep growing against 3M who produced the dual-ended Combat Arms earplugs. These earplugs were worn by service men and women from 2003 to 2015. It is claimed that defects in these earplugs resulted in acoustic injuries leading to damage to the ear, the development of tinnitus and the loss of hearing over time due to the stem of the earplugs being too short.

Click here to view this video on our YouTube page

This 3D animation addresses the claims of the defective earplugs used by the military as well as an overview of ear anatomy which allows us to appreciate the complex structures working together to produce the sense of hearing and the destructive nature of these associated injuries.

The ear can be divided into three regions: the external ear, the middle ear, and the inner ear. The external ear consists of an outer, funnel-like structure called the auricle and a 2.5 cm tube called the external auditory meatus or ear canal. The middle ear connects the external ear with the inner ear and consists of the eardrum and three small bones called auditory ossicles. The inner ear includes a complex system of intercommunicating chambers and tubes called the labyrinth. This labyrinth includes the cochlea and the semicircular canals. Within the cochlea is the basilar membrane that contains thousands of tiny hair-like projections from a series of specialized receptor cells. All these structures work in unison to accomplish the sense of hearing.

Illustration comparing normal left ear anatomy with the patient's left ear pathologies

There are several steps in the generation of an impulse perceived by the brain as hearing. First, sound waves are funneled by the auricle into the ear canal. These waves of changing pressure cause the eardrum to produce vibrations. These vibrations are amplified and transmitted by the ossicles in the middle ear into the inner ear. Within the cochlea of the inner ear, these vibrations disrupt the endolymph fluid filling the cochlear ducts causing movement of the hairs of the receptor cells. These receptors generate sensory impulses that travel along the vestibulocochlear nerve to the brain. Regretfully, loud noise, trauma or disease can damage the structures of the ear resulting in hearing loss or conditions like tinnitus that produce abnormal ringing or buzzing noises.

Trial Exhibits has worked on a variety of cases involving ear injuries. These include the development of deep ear infections resulting in a rupture of the tympanic membrane, the development of severe external ear infections, nerve impingement resulting from acoustic neuromas, and even severe injury caused by surgical procedures. 

Animation of a tympanic membrane rupture - Click here to view this video on our YouTube page

If you have a case involving the ear, hearing or any of the other special senses, contact us to assist in the creation of a custom exhibit.