PSYCH 3A03 Lecture Notes - Ambient Pressure, Ectotympanic, Epitympanic Recess

• School: McMaster University
• Department: Psychology
• Course: PSYCH 3A03
• Professor: Paul Faure

Document Summary

Pinnae reflect sounds depending on the location. Reflect sounds in a frequency specific matter. Impinging sounds are altered in amplitude and time by head and torso. Small time delays are created for high frequency sounds diffracted by head. Main function is the amplification of air pressures that reach tympanic membrane (i. e. amplification of acoustic energy for middle ear) Malleus: first middle ear ossicles also know as the hammer. Light weight mass behind the tympanic membrane as to vibrate more efficiently. Arm of the malleus (manubrium) contacts the tympanic membrane. Point of the concavity of the tympanic membrane is known as the umbo. Membrane has concavity and is oval shaped. Composed of tissue layers (radial and circular fibers) thin but tough enough to withstand changes in pressure. Connects to 1st middle ear bone (malleus)] Umbo portion of tympanic membrane has maximal concavity. Round window: bulges when stapes pushes on the round window.