Introduction and Overview CSD 3103 anatomy of speech and hearing mechanisms Hearing mechanisms Fall 2008 Introduction and Overview

Instructor website You may access these PowerPoint slides at the following website address: http://www.d.umn.edu/~floven/ Other useful course information can be found at this site as well

overview Outer Ear Middle Ear Inner Ear Hearing mechanism viewed by anatomists is divided into three parts-- outer, middle, and inner ear. The division is based on the anatomical relationships between the various structures.

The major parts of the peripheral ear overview Fig 2-3, look at major structures. Define boundaries. Overview sound wave entering the ear. The major parts of the peripheral ear

overview Fig 6-33 Review anatomical divisions, structures, the form of energy transmission, and function. A review of anatomical divisions, structures, form of energy transmission, and function

overview Simple flow chart of the major events that underlie hearing • Fig 4.1--another author’s division of parts of the ear based on structure, function, and process. Simple flow chart of the major events that underlie hearing

Skull and brain perspective of the ear The auditory system in relation to the brain and skull To be meaningful, a study of the ear must begin with a study of the temporal bone of the skull. Fig 2-2 gives skull/brain perspective of ear structures. Most of the structures that make up the ear are contained within the temporal bone. The walls of the outer, middle and inner ears and all of the bony aspects of the ear, except for the ossicles, are parts of the temporal bone.

Temporal bone Temporal bone section of the human skull Fig 2-9 Temporal bone section the skeleton of the head is composed of 8 cranial bones and 14 facial bones. The right and left temp bones comprise the inferior lateral aspects of the cranium. Beginning posteriorly and moving clockwise, the temporal bone articulates with the occipital bone behind, the parietal bone behind and above, the sphenoid and zygomatic bones to the front, and the mandible anteriorly below. All connections are sutures, except with mandible. The mandible and the temporal bone articulate thru the temporomandibular joint.

Temporal bone Lateral view of the temporal bone Important structures in this view. #16 is the mastoid process which is an intricate system of interconnecting air cells. Interconnects with the walls of the middle ear cavity and the inner ear. Bony portion of the external auditory meatus (between #14 and #9).

Temporal bone Medial view of the temporal bone Important structures in this view. #7 is the internal auditory meatus, which is part of the cochlea Show video “Body Atlas”