Audiometric investigations (AAD-80) of 140 individuals were carried out. Air and bone conduction was measured In low frequency range (250 - 2000 Hz) shift a curve of air conduction was stated in respect to bone conduction, what indicate deterioration of the conductive system.
The work concerns the collection of comparative data base for future investigations of a vocal canal and its pathologies. The investigations were carried out using the portable device type MiniDisc (Sony) and the sound analyzer SVAN 912 (Svantek). The data base is collected on the basis of subtle acoustic spectra of polish vowels of persons without any speech abnormalities. The results may be useful for setting the postoperative treatment and for diagnosis of a vocal organ.
Comparative investigations of teeth in vitro were carried out using ultrasonic method and X-Ray diffraction. A correlation between size and orientation of HAP crystallites and ultrasonic waves velocity was stated. X-Ray diffraction showed that there is a larger differentiation within a single tooth than between different teeth of an individual. This result was confirmed by ultrasonic measurements.
In the study effect on phosphocholine bilayers of cholesterol additive and of 7-DHC additive was compared depending on the lenght of phosphocholine acyl chain. Ultrasound absorption measurements were the basis of invastigations. They have shown that structurally similar cholesterol and 7-DHC molecue, by being more flat and elastic than a cholesterol molecule, more strongly binds with lipid molecules.
The aim of this paper was to find whether an ultrasound velocity along a whole tooth reflects variety of its morphology and properties and to compare thc results of ultrasonic measuremcnts with X-ray diffraction data from a large area of tooth. 100 kHz pulses were transmitted in longitudinal direction of ectracted teeth. A significant variation of velocity in teeth from diffcrent donors was statwd (from 3200 m/s to 4200 m/s). The velocity was influenced both by the age of donors and the type of a tooth. For a given individual, the grcatest difference was revealed between incisors and canine teeth. Considering X-ray diffraction results, a difference in size of crystallites between teeth was found. In an enamel, the size of crystallites ranged from 20 nm to 50 nm, and in dentin - from 5.5 nm to 39 nm. The size of crystailites in dentin was positively correlated with the ultrasound velocity.