1 / 13

Öronfysik

Öronfysik. Fysiska processer från ljudvågor i luften till nervsignaler från örat. Sverker Johansson. Örats anatomi. Principskiss av örat. Hörselbenen. Hammaren, Städet, Stigbygeln Hammaren sitter fast i trumhinnan, och tar emot ljud. Rörelsen fortplantas via Städet till Stigbygeln.

everly
Download Presentation

Öronfysik

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Öronfysik Fysiska processer från ljudvågor i luften till nervsignaler från örat. Sverker Johansson

  2. Örats anatomi

  3. Principskiss av örat

  4. Hörselbenen • Hammaren, Städet, Stigbygeln • Hammaren sitter fast i trumhinnan, och tar emot ljud. • Rörelsen fortplantas via Städet till Stigbygeln. • Stigbygeln trycker på Ovala Fönstret till innerörat. • Kombination av kolvar och hävarmar som ger ca 15 ggr tryckförstärkning • Impedansmatchning

  5. Animerat ljud i örat • Trumhinnan sätter hörselbenen i rörelse. • Stigbygelns rörelse ger en tryckvåg in i snäckan • Vågtopp på visst ställe, olika för olika frekvenser

  6. Innerörat i närbild

  7. Hårceller i närbild

  8. Localization of Vibration on Basilar Membrane • B. Membrane contains 30,000 hair/nerve cells along 35 mm length • Each octave is an  equal shift of  3.5 mm • Each pure tone is localized to a Critical Band of  1.2 mm. • Each pure tone excites  1300 hair cells covering a 15% frequency range (< minor third).

  9. Auditory Processing • Each auditory nerve cell is a little oscillator, tuned to respond to vibrations in a narrow frequency band corresponding to the nerve’s position on the Basilar Membrane. • Each auditory nerve cell fires on/off in phase with sound stimulus—provided the amplitude of vibration of the hair/nerve is above threshold. • Brain receives frequency & phase information from firing of nerves and frequency information from pattern of which nerves fire. • Expect brain can resolve position and width of pure tone distribution to 1/20 of full width = 0.06 mm  frequency ratio 1.01  29 cents: Just Noticeable Difference (JND)

  10. Hårceller före och efter ett besök på Kåren

  11. Örats känslighet

More Related