Outer Ear - Anatomy and Physiology of Speech and Hearing Lecture 4

In what kind of fashion does disturbance of air move?

wavelike fashion

What is sound?

a flow of power or a transfer of energy from one place to another

What is vibratory motion?

back and forth motion

What is our range of sound pressure?

wide; 20-20,000 Hz

What is differentiating (regarding the auditory mechanism)?

small increments in frequency and intensity

Fill in the blank: Listening to a signal embedded in ___________________

background noise

Does the auditory mechanism deal with fast or slow sequences of sound?

extremely rapid

What is audition?

the process associated with hearing

• Essential element of verbal communication

Explain energy transducer

converts acoustic energy into electrochemical energy

Identify the pinna (auricle), external auditory meatus, and tympanic membrane

Pinna or auricle function

a collector of sound to be processed at deeper levels

What is the pinna (Auricle) composed of?

primarily made of a cartilagenous framework

What is the External Auditory Meatus?

ear canal

What are the dimensions of the external auditory meatus?

approximately 7 mm in diameter and 2.5 cm long

What is the most medial portion of the EAM?

Tympanic Membrane

Identify the helix, scaphoid fossa, concha cava, tragus, and lobule

Why is the Outer 1/3 of the EAM lined with hairs and has cerumen?

traps insects and dirt which protects the medial most point of the outer ear, the Tympanic Membrane

Describe the Osseus Meatus

medial 2/3 of the canal surrounded by the temporal bone

What is the junction of the cartilaginous and bony framework of the ear canal?

Isthmus

How many layers of tissue contribute to the tympanic membrane?

3 layers of tissue compose the thin sheet

Where does the Fibrocartilaginous ring fit?

into the tympanic sulcus, a

groove in the temporal bone.

Where is the epithelial cover of the pinna found/function?

continues into the EAM and is the outer layer of the TM

Which layer of the tympanic membrane is fibrous tissue that provides structure?

middle layer

Which layer is the layer is the mucosa lining of the middle ear?

inner layer

Is the tympanic membrane concave or convex?

slightly concave

What is the most depressed portion of this concavity (tympanic membrane)?

Umbo

Review the parts of the tympanic membrane (feel free to ignore the words on the bottom)

Name some of the functions of the outer ear

- collector of sound

- directs sound waves

- localizes the source of sounds

- excellent funnel for sound

Describe the structure of the pinna

has ridges, grooves, and dished-out

regions

Why is the pinna shaped as it is?

excellent funnel for sound, localizes source of sounds

What are the 3 basic components of the outer ear?

Pinna, EAM, TM