Ear and Hearing

The Outer Ear

Sound energy spreads out from its sources. For a point source of sound, it spreads out according to the inverse square law. For a given sound intensity, a larger ear captures more of the wave and hence more sound energy.

The outer ear structures act as part of the ear's preamplifier to enhance the sensitivity of hearing.

The auditory canal acts as a closed tube resonator, enhancing sounds in the range 2-5 kiloHertz.

The Tympanic Membrane

The tympanic membrane or "eardrum" receives vibrations traveling up the auditory canal and transfers them through the tiny ossicles to the oval window, the port into the inner ear.

The eardrum is some fifteen times larger than the oval window of the inner ear, giving an amplification of about fifteen compared to a case where the sound pressure interacted with the oval window alone. 鼓膜的面积大约是内耳椭圆窗的十五倍，因此与仅声压直接作用于椭圆窗的情况相比，产生了约十五倍的放大效果。 The tympanic membrane is very thin, about 0.1 mm, but it is resilient and strong.(Zemlin) It is made up of three layers: the outer layer of skin, a layer of fibrous connective tissue, and a layer of mucous membrane.(Clark & Martin) 鼓膜非常薄，大约0.1毫米，但具有弹性和强度。(Zemlin) 它由三层组成：外层皮肤，一层纤维结缔组织，以及一层黏膜层。(Clark & Martin)

Active graphic You may reach information about the nearby structures of the ear by clicking on the item of interest on the illustration. 您可以点击示意图中感兴趣的项目，了解耳部附近结构的信息。 活动图形