Auditory pathways Flashcards
What are air waves?
alternating regions of compression and rarefaction of air molecules
How does a tuning fork set up sound waves?
Air molecules ahead of the advancing arm are compressed while the molecules behind the arm are rarefied (lower pressure than usual)
What can hearing tests based on the formation of sound waves by a tuning fork reveal?
Alterations in hearing quality in both or individual ears.
How are the auditory signals transmitted to the inner ear cells?
- Air conduction via the outer and middle ear
2. Bone conduction –> transmission due to resonance of the scull bones
What is rinne test?
Leave tuning fork to vibrate on processus mastoideus as long as patient can hear the sound (bone conduction) –> move the fork in front of outer ear (air conduction)
What is weber test?
Vibrate tuning fork in area of scull-cap–> evaluate audibility in both ears
Block ear canal of one ear and evaluate the sound audibility
What can rinne test distinguish?
A conduction disorder?
What can weber test distinguish?
lateralization
middle ear disorder –> higher intensity in affected ear
inner ear disorder –> intensity is lower in affected ear
What is the Schwabach test and why is it not an objective test?
Tuning fork first on processus mastoideus of patient, then on doctors –> if doctor still hear sound patients hearing is decreased. Based on the comparison of the auditibility of a patient and a doctors ears –>very subjective
How is the pitch of a sound determined?
By the frequency of vibrations. Greater vibrations –> higher pitch
How is the intensity of a sound evaluated?
by the amplitude of the sound waves. Greater amplitude –> louder sound
How is the unit of loudness expressed?
in decibels (dB) logarithmic measure of sound intensity
What is the hearing threshold?
The faintest sound that can be heard
What does every ten decibel indicate?
A tenfold increase in loudness
What is the timbre quality?
depends on the overtones which are additional frequencies superiimposed over the fundamental pitch –> responsible for the differences in voices
