The present work discusses results concerning sound perception obtained in selected auditory tasks, such as pitch discrimination and pitch-timbre categorization for blind and visually impaired subjects (children and teenagers). Listeners were divided into two age groups: 713 year olds and 1418 year olds. The study tested 20 individuals (8 congenitally blind and 12 visually impaired) and 20 sighted persons comprising reference groups. The timing of the experiments was as short as possible due to the fact that our listeners were children. To date, no study has described results of such experiments for blind/visually handicapped children and teenagers. It was shown that the performance of blind/visually impaired participants was not as good as that of blind adults in pitch discrimination and pitch-timbre categorization tasks. These results may have implications for the development of auditory training in orientation and mobility of young visually handicapped people.

The present work discusses results concerning sound perception obtained in a pitch memorization experiment for blind and visually impaired subjects (children and teenagers). Listeners were divided into two age groups: 7-13 year olds and 14-18 year olds. The study tested 20 individuals (8 congenitally blind and 12 visually impaired) and 20 sighted persons comprising reference groups. The duration of the experiments was as short as possible due to the fact that our listeners were children. To date, no study has described results of such experiment for blind/visually handicapped children and teenagers. In the pitch memory experiment blind teenagers outperformed blind children and both age groups of visually impaired subjects in two out of three tested cases. These results may have implications for the development of auditory training in orientation and mobility of young visually handicapped people.

Elaboration of a new method of teaching spatial orientation to blind and visually handicapped persons base on urban environment sounds was shown. Task 1 is a questionnaire inquiry on the problems of the blind moving in a big city. In Task 2 a preliminary selection and classication of the acoustic signals and vibrations that can be useful for spatial orientation was made. In Task 3 an analysis of acoustic signals for sound signalisation at pedestrian crossings was made. Some solutions for acoustic signalization were proposed. In Task 4 sounds and vibrations necessary for a library of acoustic events and situations characteristic of a city were recorded. In Task 5 the library was created and arranged to be ready to be used by teachers in the spatial orientation training. The most important outcome of the study was to develop a method of spatial orientation teaching with employment of sounds and verication of the method (Task 6). After verication it is concluded that the method is useful for spatial education of the blind at dierent levels of their education.

The paper presents results concerning vibratory detection thresholds measured on a wrist and proximal phalange and ngertips of the index, middle and ring ngers for blind and visually impaired teenagers. Subjects with vision dysfunctions were divided into two groups: congenitally blind and visually impaired. The study tested 10 handicapped individuals (5 congenitally blind and 5 visually impaired) and 10 sighted persons making reference groups chosen to be adequate in terms of age, gender, body mass and height. To date, no study has described results of such experiments for blind/visually handicapped teenagers. Vibratory perception thresholds were tracked using the Bekesy algorithm. The thresholds were investigated as a function of stimulating force frequency and magnitude or an area of a stimulating probe. Threshold values obtained for the wrist were higher than values obtained for proximal phalange and ngertips. It was shown that the performance of blind/visually impaired teenagers was not better than their sighted counterparts. Suggestions about technical form and physical parameters of a vibrating device signalling places particularly dangerous for blind/visually handicapped people were formulated.