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Wyszukujesz frazę "Żera, J." wg kryterium: Autor


Wyświetlanie 1-7 z 7
Tytuł:
Preferred Levels of Auditory Danger Signals
Autorzy:
Żera, J.
Nagórski, A.
Powiązania:
https://bibliotekanauki.pl/articles/90145.pdf
Data publikacji:
2000
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
auditory signals
danger signals
acoustics
loudness
sygnały ostrzegawcze
sygnał dźwiękowy
akustyka
Opis:
An important issue at the design stage of the auditory danger signal for a safety system is the signal audibility under various conditions of background noise. The auditory danger signal should be clearly audible but it should not be too loud to avoid fright, startling effects, and nuisance complaints. Criteria for designing auditory danger signals are the subject of the ISO 7731 (International Organization for Standardization [ISO], 1986) international standard and the EN 457 European standard (European Committee for Standardization [CEN], 1992). It is required that the A-weighted sound pressure level of the auditory danger signal is higher in level than the background noise by 15 dB. In this paper, the results of an experiment are reported, in which listeners adjusted most preferred levels of 3 danger signals (tone, sweep, complex sound) in the presence of a noise background (pink noise and industrial noise). The measurements were done for 60-, 70-, 80- and 90-dB A-weighted levels of noise. Results show that for 60-dB level of noise the most preferred level of the danger signal is 10 to 20 dB above the noise level. However, for 90-dB level of noise, listeners selected a level of the danger signal that was equal to the noise level. Results imply that the criterion in the existing standards is conservative as it requires the level of the danger signal to be higher than the level of noise regardless of the noise level.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2000, Zeszyt Specjalny; 111-117
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Attenuation of Noise by Motorcycle Safety Helmets
Autorzy:
Młyński, R.
Kozłowski, E.
Żera, J.
Powiązania:
https://bibliotekanauki.pl/articles/89964.pdf
Data publikacji:
2009
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
noise attenuation
measurements on subjects
motorcycle helmets
motorcyclist conditions of work
Opis:
For workers such as police motorcyclists or couriers, traffic and engine noise reaching the ears is an important factor contributing to the overall condition of their work. This noise can be reduced with motorcycle helmets. In this study, insertion loss of motorcycle helmets was measured with the microphone-in-real-ear technique and sound attenuation with the real-ear-at-threshold method. Results for 3 Nolan helmets show essentially no protection against external noise in the frequency range <250 Hz. In the frequency range >500 Hz, attenuation increases linearly at a rate of 8–9 dB per octave, to ~30 dB at 8 kHz. Lack of attenuation in the low-frequency range may cause annoying effects. In addition, high attenuation in the high-frequency range may decrease intelligibility of speech signals for a rider in a helmet. Attenuation measured in this study does not take into account noise generated by turbulent wind around the helmet. Thus, the measured values of attenuation represent a motorcycle rider’s best conditions of hearing.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2009, 15, 3; 287-293
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Musician’s Earplugs on Sound Level and Spectrum During Musical Performances
Autorzy:
Kozłowski, E.
Żera, J.
Młyński, R.
Powiązania:
https://bibliotekanauki.pl/articles/90990.pdf
Data publikacji:
2011
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
earplugs
hearing protection
noise
sound pressure level
musicians
Opis:
In this study, change in A-weighted and 1/3-octave sound pressure levels (SPLs) was used to assess the influence of wearing earplugs by musicians on their musical performances. Seven soloists and 3 music assembles performed 4 pieces of music with musician’s earplugs donned and doffed. They used silicon custom moulded earplugs with acoustic filters designed to attenuate sound by 9, 15 or 25 dB. Results showed that the use of earplugs affected the sound level and the spectrum of played sounds. This effect was the greatest for brass players. The difference between SPLs in high-frequency 1/3-octave bands and A-weighted SPLs with and without earplugs exceeded 5 and 15 dB, respectively. Similar changes for woodwind, percussion and string instruments were less noticeable than for brass instruments; they were more than 5 dB for 1/3-octave spectra and no more than 2 dB for A-weighted SPL.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2011, 17, 3; 249-254
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zagrożenie hałasem impulsowym wytwarzanym w przemyśle oraz podczas strzałów i eksplozji
Threat posed by impulse noise produced by the industry and during explosions
Autorzy:
Młyński, R.
Żera, J.
Kozłowski, E.
Powiązania:
https://bibliotekanauki.pl/articles/179685.pdf
Data publikacji:
2012
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
hałas
hałas impulsowy
noise
impulsive noise
Opis:
Hałas impulsowy jest zagrożeniem dla słuchu występującym na wielu stanowiskach pracy, najczęściej związanych z obróbką metali oraz w obecności wystrzałów bądź eksplozji. Należy mieć na uwadze, że w przypadku silnych impulsów istnieje możliwość spowodowania trwałego ubytku słuchu nawet po jednej ekspozycji. W artykule przedstawiono właściwości hałasu impulsowego wytwarzanego przez 37 źródeł hałasu typowych dla przemysłu i zastosowań militarnych. Obliczono też liczbę minut lub dopuszczalną liczbę strzałów/eksplozji, na jakie mógłby być eksponowany pracownik na określonym stanowisku pracy.
Impulse noise encountered at workplaces, usually related to either metal processing or gunshots and explosions, is a threat to hearing. It should be noted that strong impulses can induce a hearing loss even if caused by a single exposure. The article discusses properties of impulse noise generated by 37 sources typically found in the industry or at the military. The number of minutes and the admissible number of either gunshots or explosions towards which an employee might be exposed at a certain workstation was calculated and provided.
Źródło:
Bezpieczeństwo Pracy : nauka i praktyka; 2012, 3; 22-25
0137-7043
Pojawia się w:
Bezpieczeństwo Pracy : nauka i praktyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Influence of Directional Microphones on the Speech Intelligibility and Spatial Perception by Cochlear Implant Users
Autorzy:
Kordus, M.
Tyler, R. S.
Żera, J.
Oleson, J. J.
Powiązania:
https://bibliotekanauki.pl/articles/177968.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
localization
bilateral cochlear implants
adults
microphone
beamformer
Opis:
The objective of the study is to assess the hearing performance of cochlear implant users in three device microphone configurations: omni-directional, directional, and beamformer (BEAMformer two-adaptive noise reduction system), in localization and speech perception tasks in dynamically changing listening environments. Seven cochlear implant users aided with Cochlear CM-24 devices with Freedom speech processor participated in the study. For the localization test in quiet and in background noise, subjects demonstrated significant differences between different microphone settings. Confusion matrices showed that in about 70% cases cochlear implant subjects correctly localized sounds within a horizontal angle of 30–40◦ (±1◦ loudspeaker apart from signal source). However localization in noise was less accurate as shown by a large number of considerable errors in localization in the confusion matrices. Average results indicated no significant difference between three microphone configurations. For speech presented from the front 3 dB SNR improvements in speech intelligibility in three subjects can be observed for beamforming system compared to directional and omni-directional microphone settings. The benefits of using different microphone settings in cochlear implant devices in dynamically changing listening conditions depend on the particular sound environment.
Źródło:
Archives of Acoustics; 2015, 40, 1; 81-92
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Loudness Functions and Binaural Loudness Summation in Bilateral Cochlear Implant Users
Autorzy:
Kordus, M.
Zera, J.
Powiązania:
https://bibliotekanauki.pl/articles/177754.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
loudness
binaural loudness
loudness function
binaural summation
cochlear implant
Opis:
Loudness functions and binaural loudness summation was investigated in acoustically stimulated bilaterally implanted cochlear implant users. The study was aimed at evaluating growth of loudness functions and binaural loudness summation in cochlear implant subjects as a function of stimulus presentation level at different frequencies. Loudness was assessed using a rating procedure on a scale of 0 to 100. Three experimental conditions were tested: monaural right, monaural left and binaural, each with bands of noise with center frequencies of 0.25, 1, and 4 kHz. Fifteen implanted and five normal-hearing subjects (control group) participated in the experiments. Results demonstrated large variability in the slopes of the loudness functions and the presence of loudness summation in bilateral cochlear implant users, with large individual differences among subjects.
Źródło:
Archives of Acoustics; 2017, 42, 3; 351-364
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detection and Recognition of Environmental Sounds by Musicians and Non-Musicians
Autorzy:
Miśkiewicz, A.
Rościszewska, T.
Żera, J.
Majer, J.
Okoń-Makowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/176313.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
environmental sounds
detection threshold
recognition threshold
Opis:
The article reports three experiments conducted to determine whether musicians possess better ability of recognising the sources of natural sounds than non-musicians. The study was inspired by reports which indicate that musical training develops not only musical hearing, but also enhances various non-musical auditory capabilities. Recognition and detection thresholds were measured for recordings of environment al sounds presented in quiet (Experiment 1) and in the background of a noise masker (Experiment 2). The listener’s ability of sound source recognition was inferred from the recognition-detection threshold gap (RDTG) defined as the difference in signal level between the thresholds of sound recognition and sound detection. Contrary to what was expected from reports of enhanced auditory abilities of musicians, the RDTGs were not smaller for musicians than for non-musicians. In Experiment 3, detection thresholds were measured with an adaptive procedure comprising three interleaved stimulus tracks with different sounds. It was found that the threshold elevation caused by stimulus interleaving was similar for musicians and non-musicians. The lack of superiority of musicians over non-musicians in the auditory tasks Explorer in this study is explained in terms of a listening strategy known as casual listening mode, which is a basis for auditory orientation in the environment.
Źródło:
Archives of Acoustics; 2018, 43, 4; 581-592
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

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