نتایج جستجو برای: loudness level and sound pressure level

تعداد نتایج: 16965466  

Journal: :تحقیقات نظام سلامت 0
نگار جعفری دانشجوی کارشناسی ارشد، کمیته تحقیقات دانشجویی، مهندسی بهداشت محیط، مرکز تحقیقات محیط زیست، دانشکده بهداشت، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران بیژن بینا استاد، مرکز تحقیقات محیط زیست، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران سهیلا مرتضایی کارشناسی ارشد، مهندسی بهداشت حرفه ای، کارشناس آزمایشگاه گروه بهداشت حرفه ای، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران افشین ابراهیمی استادیار، مرکز تحقیقات محیط زیست، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران علی عبداله نژاد دانشجوی کارشناسی ارشد، کمیته تحقیقات دانشجویی، مهندسی بهداشت محیط، مرکز تحقیقات محیط زیست، دانشکده بهداشت، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران

background: to prevent the adverse health effects of noise pollution and to achieve the recommended standards, assessment of noise levels in the cities is essential. the aim of this study was to evaluate noise pollution levels (npls) in isfahan, iran and compare them with recommended standard values. materials and methods: a total number of 19 measurement points were selected from most congeste...

Journal: :Journal of applied physiology 2005
Jessica E Huber Bharath Chandrasekaran John J Wolstencroft

The purpose of the present study was to determine whether different cues to increase loudness in speech result in different internal targets (or goals) for respiratory movement and whether the neural control of the respiratory system is sensitive to changes in the speaker's internal loudness target. This study examined respiratory mechanisms during speech in 30 young adults at comfortable level...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز - دانشکده ادبیات و زبانهای خارجی 1391

abstract this study investigates the teachers’ correction of students’ spoken errors of linguistic forms in efl classes, aiming at (a) examining the relationship between the learners’ proficiency level and the provision of corrective feedback types, (b) exploring the extent to which teachers’ use of different corrective feedback types is related to the immediate types of context in which err...

Journal: :بهداشت و توسعه 0
رضا حسین پور کاظم جعفری نعیمی محمدرضا قطبی راوندی

background: one of the most widely used equipments in harvesting hay and grains are four wheel mowers. the aim of the present study was to determine the levels of noise exposure in drivers and bystanders in different states, speeds and gear of four wheel mowers (bcs model 622).   methods: the iso 5131 and iso 6814 standards were used to assess noise exposure in drivers and bystanders, respectiv...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت دبیر شهید رجایی - دانشکده علوم انسانی 1391

according to cheng (1999), in recent esl/efl literature, asian (especially east asian) learners of english as a foreign/second language have been arguably reported as reticent and passive learners. the most common allegations are that these students are reluctant to participate in classroom discourse; they are unwilling to give responses; they do not ask questions; and they are passive and over...

Journal: :The Journal of the Acoustical Society of America 2001
S D Sommerfeldt T O Samuels

An attempt has been made to use a modified version of a standard active noise control algorithm in order to take into account the unique response of the human auditory system. It has been shown in the past that decreasing the sound pressure level at a location does not guarantee a similar decrease in the perceived loudness at that location. Typically, active noise control is based on minimizing...

Journal: :Journal of the American Academy of Audiology 1992
P R Filion R H Margolis

The purpose of this study was to determine the relationship between the loudness discomfort level (LDL) and real-life impressions of loudness discomfort. LDLs were measured with an established procedure for a variety of stimuli including FM tones, speech noise, and stimuli recorded from two real-life environments, in two groups of subjects. Sound pressure level distributions were measured in ea...

Journal: :iranian journal of environmental sciences 0
a. r. noorpoor associate professor, graduate faculty of environmental, university of tehran, tehran, iran m. bayatian phd student in professional hygiene, faculty of public health, islamic azad university, tehran, iran s. motaghed msc student in chemical engineering, university of petroleum, tehran, iran a. jamshidi moghadam bsc student in professional hygiene, university of medical science, tehran, iran n. rahmati msc. student in environmental science, faculty of science and research, islamic azad university, tehran, iran

we investigated the issue of noise pollution in the bidboland gas refineryby noise measurement and surveys. the bidboland gas refinery has several process units.the sound pressure levels were measured at several places, such as units of 200, 300,400, 500, boiler, powerhouse area, cooling towers pumps, and maintenance area, and thecorresponding noise maps were produced by using sound plan softwa...

Journal: :international journal of occupational hygiene 0
parvin nassiri department of occupational health, school of public health, tehran university of medical sciences, tehran, iran. hamidreza heidari research center for environmental pollutants, qom university of medical sciences, qom, iran. monireh khadem department of occupational health, school of public health, tehran university of medical sciences, tehran, iran. hoda rahimifard department of occupational health, school of public health, qom university of medical sciences, qom, iran. elham rostami department of epidemiology and biostatistics, school of public health, tehran university of medical science, tehran, iran.

noise is a common and widespread problem in workplaces. noise can lead to hearing loss, hypertension, nervous and mental disorders, annoyance and stress, sleep disturbance, negative impact on productivity and working capacity. the undesirable effects of noise on an individual or group are called annoyance. some personal and social characteristics can affect on annoyance. this study was aimed to...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده تربیت بدنی علوم ورزشی 1390

this research was conducted to examine the effect of a concurrent training on rest level of leptin of plasma and some hormonal factors in non-athlete subjects. the research population included non-athlete men who didn’t participate in any organized sport activities. 30 men were chosen voluntarily among the above-mentioned population and were divided into 2 groups: experimental (15 subjects) an...

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