Uticaj akustičkog i biološkog šuma na kvalitet merenja signala otoakustičke emisije
The influence of acoustic and biological noise on signal quality measurements of otoacoustic emissions
Doktorand
Subotić, Miško![](/themes/MirageNardus/images/orcid.png)
Mentor
Jovičić, SlobodanČlanovi komisije
Mijić, Miomir![](/themes/MirageNardus/images/orcid.png)
Pavlović-Šumarac, Dragana
![](/themes/MirageNardus/images/orcid.png)
Šarić, Zoran
![](/themes/MirageNardus/images/orcid.png)
Radunović, Jovan
![](/themes/MirageNardus/images/orcid.png)
Metapodaci
Prikaz svih podataka o disertacijiSažetak
Biološka osnova nastanka signala otoakusticke emisije (OAE), akusticka priroda
njegovog nastanka i izuzetna maskiranost raznim oblicima smetnji jesu polazna osnova
razvoja raznih metoda detekcije, obrade i interpretacije signala OAE, odnosno samog
efekta otoakusticke emisije u svetlu karakterizacije funkcionisanja kohlee. Metode
merenja OAE se razlikuju po nacinu generisanja stimulusa, mehanizmima generisanja
odziva kao i po nacinima obrade signala i statistickog tumacenja dobijenih rezultata.
Postojece metode merenja i obrade signala OAE jesu osnova savremenih sistema
za merenje OAE, koji su našli široku primenu u klinickoj praksi. Meutim, nisu
iscrpljene sve mogucnosti, pre svega teorijske a zatim i metodološke prirode,
prvenstveno u domenu ekstrakcije signala OAE iz šuma.
Poboljšanjem uslova merenja smanjuje se uticaj spoljašnje buke (šumova) na
mogucnost ekstrakcije signala otoakusticke emisije i biološki šum postaje dominantan
izvor smetnji. Istraživanje karakteristika... bioloških šumova je jedan od preduslova za
uspešno rešavanje problema detekcije OAE u prisustvu biološkog šuma. Na pažljivo
odabranom uzorku, u skladu sa potrebama istraživanja, analizirani su biološki šumovi
snimljeni u ušnom kanalu. Pokazalo se da postoji znacajna korelacija bioloških šumova
u levom i desnom uhu i da koeficijent korelacije raste sa porastom intenziteta bioloških
šumova. Ovakvo ponašanje bioloških šumova predstavlja povoljnu okolnost sa
stanovišta primene adaptivnih metoda filtriranja i adaptivnih metoda potiskivanja šuma.
U disertaciji su analizirane karakteristike najznacajnijih bioloških smetnji koje su
prisutne kod merenja signala OAE. Ova saznanja su omogucila izbor optimalane
adaptivne metode za detekciju TEOAE u prisustvu biološkog šuma. Osnovna ideja za
potiskivanje biološkog šuma sastojala se u korišcenju biološkog šuma iz drugog ušnog
c
kanala za adaptivno potiskivanje biološkog šuma u ušnom kanalu u kome se meri OAE
signal. Pošto je signal OAE duboko uronjen u šum, neophodno je bilo kombinovati
nekoliko postupaka u toku predobrade signala kako bi se postiglo dobro potiskivanje
šuma. Primenjeni su postupci adaptivnog filtriranja, ponderisanog usrednjavanja i
oduzimanja procenjene vrednosti signala OAE od signala odziva snimljenog u ušnom
kanalu...
Biological basis of the otoacoustic emission signal (OAE), acoustic nature of its
generation and exceptional masking with various forms of interference are the starting
point for the development of various methods of detection, signal processing and
interpretation of OAE signal, or the effect of otoacoustic emission in light of the
characterization of the cochlea functioning. OAE measurement methods differ in the
way of stimulus generation, response generation mechanisms and the methods of signal
processing and statistical interpretation of results.
Existing methods of measurement and OAE signal processing are the basis of
modern systems for OAE measurement, which have found wide application in clinical
practice. However, all possibilities are not exhausted, especially the theoretical and
methodological nature aproaches, primarily in the field of OAE signal extraction from
the noise.
Improvement of the measuring conditions reduces the influence of external noise
on the pos...sibility of extraction of otoacoustic emissions, and biological noise becomes
the dominant source of interference. The study of characteristics of biological noise is
one of the prerequisites for successful troubleshooting OAE detection in the presence of
biological noise. In carefully selected sample, in accordance with the needs of research,
we analyzed the biological noise recorded in the ear canal. It turned out that there was a
significant correlation of biological noise in the left and right ear and the correlation
coefficient increases with the intensity of biological noise. This behavior of biological
noise is a favorable circumstance from the point of application of adaptive filtering
methods and adaptive noise suppression method.
The dissertation analyzes the characteristics of the most important form of
biological interference that are present during OAE measurement. These findings have
enabled the selection of optimal adaptive methods for the detection of TEOAE in the
presence of biological noise. The basic idea of suppressing biological noise consisted in
e
the use of biological noise from the other ear canal for adaptive suppression of
biological noise in the ear canal in which OAE signal is measured. Since the OAE
signal is deeply immersed in the noise it was necessary to combine several steps during
preprocessing the signal to achieve good noise suppression. The applied methods are
adaptive filtering, weighted averaging and estimated value of OAE signal subtraction
from the signal response recorded in the ear canal...