External Ear
External Ear - Related Videos
09:10
Ear Exam
0 Views •
2023
Source: Richard Glickman-Simon, MD, Assistant Professor, Department of Public Health and Community Medicine, Tufts University School of Medicine, MA This video describes the examination of the ear, beginning with a review of its surface and interior anatomy (Figure 1). The cartilaginous auricle consists of the helix, antihelix, earlobe, and tragus. The mastoid process is positioned just behind the earlobe. The slightly curving auditory canal ends at the tympanic membrane, which transmits sound...
01:20
Externalities
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2025
Externalities are unintended side effects of economic activities that impact third parties who are not directly involved in the market transaction. They can have positive or negative effects that can influence society and the environment in various ways. Positive Externalities Positive externalities occur when a market activity produces benefits for others without those beneficiaries having to pay for it. Examples include: Education: When individuals receive an education, society benefits...
09:35
Investigating Outer Hair Cell Motility with a Combination of External Alternating Electrical Field Stimulation and High-speed Image Analysis
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Cited by 3 •
2011
A reliable method to investigate outer hair cell (OHC) motile responses, including electromotility, slow motility and bending, is described. OHC motility is elicited by stimulation with an external alternating electrical field, and the method takes advantage of high-speed image recording, LED-based illumination, and last generation image analysis software.
04:42
Transcutaneous Auricular Vagus Nerve Stimulation on the Human Ear
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2025
Source: Badran, B. W., et al. Laboratory Administration of Transcutaneous Auricular Vagus Nerve Stimulation (taVNS): Technique, Targeting, and Considerations. J. Vis. Exp. (2019)This video demonstrates transcutaneous auricular vagus nerve stimulation (taVNS), a noninvasive method for modulating brain activity. Electrodes are placed on the anterior wall of the outer ear canal and the tragus, targeting the auricular branch of the vagus nerve (ABVN). When stimulated, the resulting nerve impulse...
01:11
Work Done on a System by External Force
0 Views •
2023
The work done by an external force on a particle changes its kinetic energy. However, internal forces must also be considered for a system of interacting particles. The potential energy formulation helps formulate the effect of internal forces. The net work done by an external force can be written in terms of the total change of mechanical energy, which includes both kinetic and potential energies. In the presence of a non-conservative opposing force, like friction, some part of the work done...
FAQs
The ridges of the auricle reflect and filter incoming sound, altering the sound pattern before it travels through the external auditory canal. This acoustic modification is part of normal external-ear function rather than a sign of disease. Changes in the auricle’s shape, including congenital differences or trauma, may therefore be clinically relevant when examining sound-related symptoms.
The external auditory canal contributes resonance to transmitted sound while also providing physical protection. Cerumen and hairs help limit the entry of debris and microorganisms, supporting the canal’s protective role. When wax becomes obstructive, however, this normally protective material can interfere with the sound pathway and become a clinically relevant finding during examination.
Several abnormalities may affect external-ear function or produce symptoms, including inflammation, infection, trauma, foreign bodies, and obstructive wax. Congenital differences may also be identified during assessment. These findings help clinicians distinguish problems arising from the external ear from other possible causes of hearing symptoms and provide direction for further clinical evaluation.
Clinical assessment begins with inspection of the visible ear and is complemented by otoscopy, which evaluates the external auditory canal and the pathway toward the tympanic membrane. Together, these approaches can identify congenital differences, trauma, inflammation, infection, foreign bodies, and obstructive wax, making them useful for investigating hearing symptoms and suspected otitis externa.
Otoscopy can reveal abnormalities within the external auditory canal that may explain symptoms or indicate disease. Findings may include inflammation or infection associated with otitis externa, accumulated wax that obstructs the canal, or a foreign body. The examination also helps place visible canal findings in the broader context of the patient’s hearing complaints.
External ear assessment supports recognition of otitis externa by allowing clinicians to inspect for inflammation and infection in the auricle and canal region. It can also identify alternative or accompanying findings, such as trauma, foreign bodies, or obstructive wax. This clinical context helps determine whether external-ear abnormalities plausibly account for the patient’s symptoms.