Chapter 11: (Bone Conduction)

Question 1

Air conduction

Answer 1

the process by which an acoustic signal travels through the structures of the outer and middle ear and drives at the inner ear.

Question 2

bone conduction

Answer 2

the process by which an acoustic signal vibrates the bones of the skull to stimulate the cochlea; vibrations of the skull bones can result from either acoustic or mechanical stimulation of the skull.

Question 3

Bone conduction hearing aid

Answer 3

a hearing aid that directly vibrates the bones of the skull for patients with outer and/or middle ear pathology; bone conduction hearing aids consist of a bone vibrator and supporting signal processing circuitry.

Question 4

Bone vibrator

Answer 4

a device that is designed to vibrate the bones of the skull to transmit auditory signals

Question 5

clinical bone vibrator

Answer 5

a bone vibrator used for hearing testing

Question 6

communication bone vibrator

Answer 6

a bone vibrator used for speech communication

Question 7

compressional vibration

Answer 7

a motion of a vibrating system in which different elements of the system vibrate in opposite directions

when different elements of a vibrating system move against each other. 800 Hz

Question 8

contact microphone

Answer 8

a transducer that changes mechanical vibrations into an electric signal; a contact microphone can be used to convert the skull vibrations of a talker into an audio signal.

Question 9

distortional mechanism

Answer 9

a bone conduction mechanism that results from alternating compressions and expansions of the bony cochlear cavity and result in motion of the basilar membrane.

Question 10

Internal middle ear mechanism

ossicular-inertial mechanism

Answer 10

The primary mechanism for transmission of bone conduction energy to the cochlea.

Vibrations of the skull cause the bony portions of the cochlea to vibrate, moving cochlear fluids.

Question 11

(Internal middle ear mechanism)

1. The compressional cochlear mechanisms

Answer 11

• Distortion

- Compressions

Question 12

(Internal middle ear mechanism)

2. The inertial cochlear mechanism

Answer 12

the result of the inertial lag between the movement of the walls of the bony labyrinth and the motion of the fluid and membranes within the bony labyrinth.

Question 13

Inertial vibration

Answer 13

at low frequencies around 200 Hz the entire skull vibrates back and forth as a unit.

Question 14

Inner ear mechanism

Answer 14

bone conduction mechanism that result in changes in the size and shape of the cochlea and causes an inertial lag between the walls of the bony labyrinth and the motion of the fluid and membranes within the bony labyrinth,

Question 15

Inertial middle ear mechanism
Middle ear mechanism
ossicular-inertial mechanism

Answer 15

a bone conduction mechanism that results form the inertial lag of the ossicular chain in comparison with the motion of the skull; this causes the stapes to move in and out of the oval window.

Question 16

Occlusion effect

Answer 16

the increase in the intensity of bone-conducted sounds caused by the occlusion (covering) of the external ear.
Primarily a low-frequency phenomenon and it depends on the volume of the occluded space.
the sound pressure increase in the ear canal due to the occlusion effect may be as large as 20-25 dB

Question 17

Osteotympanic mechanism

Outer ear mechanism

Answer 17

a bone conduction mechanism in which vibrations of the skull cause vibrations of the ear canal and these vibrations generate acoustic waves; if the ear canal is unoccluded (not covered) most of sound energy exits the ear canal via the external auditory meatus; if the ear canal is occluded (covered), the sound energy is transmitted to the middle ear via tympanic membrane vibrations.