Search results for "ACOUSTIC"
showing 10 items of 1590 documents
Verbesserte Auswertbarkeit transitorisch evozierter otoakustischer Emissionen durch Korrelationsfilterung
1993
Hearing screening as well as evaluation of cochlear function under therapy with ototoxic agents or patients with various diseases is increasingly done by registration of transient evoked otoacoustic emissions (TEOAE). Usually the standard system ILO 88 Otodynamic Analyser is used, where until now emissions were analyzed subjectively. However, evaluation of signals may be difficult mainly in the hearing threshold area. In this article we describe a method to mathematically analyze registered emissions by correlation-filtering. This allows to better identify small specific responses, to further increase the sensitivity of TEOAE, and offers a more objective means for audiologic diagnoses.
Acoustic Rhinometry-Predictive Value in Septal and Turbinate Surgery
1996
Noise-induced sleep disturbances and their effects on health
1978
Acoustic Features of Voice in Patients with Snoring
2011
Objective: Determine whether the acoustic characteristics of snoring sounds differed between 30 simple male adult snorers (group A) and 30 healthy adult male subject (group B) by using a multidimensional voice program (MDVP), which is a commonly used computer program that analyzes various aspects of voice.Method: Group A patients presented a Friedman tongue position grade I, tonsil size 2 to 3, a body mass index of 15. Phonetically balanced sentences and sustained vowels a, e, and i were digitally recorded with the MDVP; evaluation of voice handicap index (VHI) was done too.Results: Compared with control group, in group A: the acoustic parameters presented a statistically significantly high…
Malignant paroxysmal positional vertigo
2011
Objective: An insidious percentage of paroxysmal positional vertigo appears to be intractable with canalith repositioning maneuver and also is not self-limiting. This type of positional vertigo is sustained by the action of intracranial tumors that mimics the clinical aspects of benign paroxysmal positional vertigo.Aim of this study is to clarify the features of these forms of positional vertigo, which we indicate as malignant paroxysmal positional vertigo. Methods: We retrospectively reviewed the clinical records of all the patients who presented with vertigo spells and were managed at our tertiary care referral centre over a three years period. Two hundred and eleven patients with diagnos…
Primary ciliary dyskinesia assessment by means of optical flow analysis of phase-contrast microscopy images
2014
Primary ciliary dyskinesia implies cilia with defective or total absence of motility, which may result in sinusitis, chronic bronchitis, bronchiectasis and male infertility. Diagnosis can be difficult and is based on an abnormal ciliary beat frequency (CBF) and beat pattern. In this paper, we present a method to determine CBF of isolated cells through the analysis of phase-contrast microscopy images, estimating cilia motion by means of an optical flow algorithm. After having analyzed 28 image sequences (14 with a normal beat pattern and 14 with a dyskinetic pattern), the normal group presented a CBF of 5.2 +/- 1.6 Hz, while the dyskinetic patients presented a 1.9 +/- 0.9 Hz CBF. The cutoff …
Left ventricular volume determination using colour superpositioning of contrast echocardiograms
1995
Abstract Objective: To delineate the endocardium, selective colouring of contrast regions in left ventricular contrast echocardiograms was performed using digital image processing. Methods: Volume determinations were performed in end-diastolic and end-systolic frames before and after the injection of contrast agent into the left ventricle and were compared to cineventriculograms in 30 patients by two independent investigators. Results: The mean end-diastolic volume measured was 114 ± 44 ml in the native, 235 ± 79 ml in the contrast, 175 ± 70 ml in the color-superimposed (observer 1), and 187 ± 79 ml in the cineventriculographic images. Thus, native echocardiograms underestimated angiographi…
ERPs to pitch changes: a result of reduced responses to standard tones in rabbits.
1996
EVENT-RELATED potentials (ERPs) were recorded in rabbits when pitch deviant tones occurred in a series of standard tones (oddball situation). In control recordings, the deviant tones were presented without the standard tones (deviant-alone situation). In the oddball situation, significant difference ERPs (deviant ERPs - standard ERPs) could be found in the hippocampal and cerebellar recordings but not in the visual cortex. All the ERPs to the deviant stimuli observed in the oddball situation were also present in the deviant-alone situation. The difference ERPs were therefore based on reduced responses to the standards. The results are discussed in the context of a mismatch negativity (MMN) …
Otoacoustic emissions: a new method to diagnose hearing impairment in children.
1993
Otoacoustic emissions (OAEs) are epiphenomena of sensitive, amplifying processes during hearing which can be detected in persons with normal inner ear function. They originate from the cochlea and are interpreted as an energy leakage of cochlear processes, perhaps resulting from active outer hair cell movements. OAEs travel from the cochlea through the middle ear to the external auditory canal where they can be detected using sensitive miniature microphones. Transient evoked (TEOAE) tests allow to otoacoustic emissions non-invasively check the integrity of the cochlea. In the neonatal period, registration of OAEs can be accomplished during natural sleep. In infants and neonates TEOAEs can b…