hearing and deafness 1 anatomy physiology l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Hearing and Deafness 1. Anatomy & physiology PowerPoint Presentation
Download Presentation
Hearing and Deafness 1. Anatomy & physiology

Loading in 2 Seconds...

play fullscreen
1 / 24

Hearing and Deafness 1. Anatomy & physiology - PowerPoint PPT Presentation


  • 119 Views
  • Uploaded on

Hearing and Deafness 1. Anatomy & physiology. Chris Darwin. Web site for lectures, lecture notes and filtering lab: http://www.lifesci.susx.ac.uk/home/Chris_Darwin/. safari. Outer, middle & inner ear. Capture; Amplify mid-freqs Vertical direction coding. Protection

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Hearing and Deafness 1. Anatomy & physiology' - paul


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
hearing and deafness 1 anatomy physiology

Hearing and Deafness 1. Anatomy & physiology

Chris Darwin

Web site for lectures, lecture notes and filtering lab:

http://www.lifesci.susx.ac.uk/home/Chris_Darwin/

safari

outer middle inner ear
Outer, middle & inner ear

Capture; Amplify mid-freqs

Vertical direction coding

Protection

Impedance match

Frequency analysis

Transduction

conductive hearing loss
Conductive hearing loss
  • Sounds don’t get into cochlea
  • Middle ear problems
  • Helped by surgery and by amplification
reponse of basilar membrane to sine waves
Reponse of basilar membraneto sine waves

Each point on the membrane responds best to a different frequency: high freq at base, low at apex.

praat

amadeus

auditory nerve innervation
Auditory nerve innervation

IHC (1)

radial afferent (blue) lateral efferent (pink)

OHC (2)

spiral afferent (green) medial efferent (red)

phase locking of inner hair cells
Phase Locking of Inner Hair Cells

Auditory nerve connected to inner hair cell tends to fire

at the same phase of the stimulating waveform.

ohc movement
OHC movement

Passive

No OHC movement

Active

With OHC movement

ohc activity
OHC activity

OHCs are relatively more active for quiet sounds than for loud sounds.

They only amplify sounds that have the characteristic frequency of their place.

  • Increases sensitivity (lowers thresholds)
  • Increases selectivity (reduces bandwidth of auditory filter)
  • Gives ear a logarithmic (non-linear) amplitude response
  • Produce Oto-acoustic emissions
auditory tuning curves
Auditory tuning curves

Inner hair-cell damage

Healthy ear

conductive vs sensori neural deafness
Conductive vs Sensori-neural deafness

Mostly a combination of OHC and IHC damage

Becomes linear, so

No combination tones

Or two-tone suppression

normal auditory non linearities
Normal auditory non-linearities
  • Normal loudness growth (follows Weber’s Law)
  • Combination tones
  • Two-tone suppression
  • Oto-acoustic emissions