The object of the study. Short impulse acoustic signals in the frequency range from 500 to 4000 Hz and intensity from 30 to 85 dB. The aim of the study. To estimate and assess the quality of the speech and acoustic signals from the perspective of various background noises of different frequency spectra. The tasks of the study: 1. To evaluate the effects of noise of various intensity on identification of short impulse signals and speech intelligibility in noise; 2. To analyse the audibility of signals in the frequency range of verbal communication (500–4000 Hz) in noise of various intensity and frequency content and to determine the characteristics of signals to be identified in noise; 3. To determine the influence of signals’ duration to the quality of its qualitative subjective identification; 4. To assess the masking effects of the background noise on speech and other informative signals under the combinations if different intensity. Practical value. The data obtained and method developed can be used for the assessment of the acoustic signals in noise. The method is also applicable to the description of background noise from the perspective of verbal communication. Such methodology and results can be adopted for the quality prognostication of audible information and its loss in various background noises of different spectral pattern. / Temos aktualumas. Triukšmo poveikis darbo aplinkoje dažnai siejamas su dirbančiųjų produktyvumo mažėjimu, o triukšmingoje aplinkoje neišgirsti arba neadekvačiai išgirsti akustiniai signalai dažnai būna mašinų trikčių ar traumų darbe pasekmė. Šie pavyzdžiai aiškiai rodo būtinybę spręsti problemas, susietas su girdimosios informacijos sklaida ir kokybe triukšmingoje aplinkoje. Įspėjamųjų ar pavojaus signalų darbo aplinkoje naudojimas standartizuotas ir dažniausiai sprendžiamas energiniu požiūriu, t. y. teikiant ženkliai didesnio intensyvumo akustinius signalus. Šių signalų girdimumas vidutinio intensyvumo triukšmingoje aplinkoje keblumų nesukelia, tačiau realiomis sąlygomis tokios aplinkybės retai pasitaikančios. Daugelyje mokslinių darbų, nagrinėjant garsinės informacijos kokybės klausimus, keliamos tik visiško arba pakankamo suprantamumo problemos, tačiau praktikoje svarbus dalinis šių signalų suvokimas (egzistavimo fakto nustatymas), kuris tyrinėtas menkai. Šiame darbe tiriami ir nagrinėjami reiškiniai, turintys įtakos akustinių garsų girdimumui triukšmingoje aplinkoje bei girdimumą sąlygojančios aplinkybės o taip pat siūlomi sprendimai garsinės informacijos kokybės sistemoje „žmogus – mašina – aplinka“ patikimumo didinimui. Darbo tikslas – triukšmo šaltinių sukuriamą triukšmo foną akustinėje erdvėje ištirti trumpalaikių informacinių akustinių garsų suvokimo požiūriu ir įvertinti triukšmingos aplinkos įtaką naudingų akustinių signalų identifikavimo kokybei. Darbo... [toliau žr. visą tekstą]

The purpose of this study was to determine the effects of an atypical pattern of early acoustic stimulation on auditory development. Previous human research suggests that the acoustic environment of pre-term human infants in the Neonatal Intensive Care Unit (NICU) negatively affects some aspects of auditory development. Animal research suggests that premature auditory stimulation interrupts auditory development. Because mice are born before their auditory systems are developed, they make an excellent model for research on fetal and postnatal plasticity of the auditory system. The premature auditory state of newborn mice is similar to that of the NICU pre-term infant, albeit, natural for mice C57 mouse pups were exposed to an augmented acoustic environment (AAE) of a nightly 12-hour regiment of 70 dB SPL noise burst, beginning before age 12 days (onset of hearing) and lasting for one month. The prepulse inhibition (PPI) of mice exposed to the AAE was compared to that of non-exposed mice to observe short-term and long-term effects. Results showed that the prepulse inhibition of the AAE exposed mice did not differ significantly from that of the non-exposed mice. However, it is possible that the measurement used, PPI, may not have been appropriate or that the AAE may not have been an appropriate simulation of the NICU environment.

Professional research project (Au.D.)--University of South Florida, 2003. / Title from PDF of title page. / Document formatted into pages; contains 20 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The purpose of this study was to determine the effects of an atypical pattern of early acoustic stimulation on auditory development. Previous human research suggests that the acoustic environment of pre-term human infants in the Neonatal Intensive Care Unit (NICU) negatively affects some aspects of auditory development. Animal research suggests that premature auditory stimulation interrupts auditory development. Because mice are born before their auditory systems are developed, they make an excellent model for research on fetal and postnatal plasticity of the auditory system. The premature auditory state of newborn mice is similar to that of the NICU pre-term infant, albeit, natural for mice C57 mouse pups were exposed to an augmented acoustic environment (AAE) of a nightly 12-hour regiment of 70 dB SPL noise burst, beginning before age 12 days (onset of hearing) and lasting for one month. / ABSTRACT: The prepulse inhibition (PPI) of mice exposed to the AAE was compared to that of non-exposed mice to observe short-term and long-term effects. Results showed that the prepulse inhibition of the AAE exposed mice did not differ significantly from that of the non-exposed mice. However, it is possible that the measurement used, PPI, may not have been appropriate or that the AAE may not have been an appropriate simulation of the NICU environment. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.