Field class methodology to study noise from kiosks and its interference in the population that frequents Santos SP beachRoberto Cesar Lourenço Roberto Cesar Lourenço

Abstract

Sound is the sensation produced by the auditory system, resulting from the pressure modification that occurs in elastic media, propagating in the form of waves or longitudinal and three-dimensional mechanical oscillations. In 1978, ABNT (Brazilian Association of Technical Standards) defined noise as a dissonant or anarchic, aperiodic and undesirable acoustic phenomenon; mixture of sounds whose frequencies differ from each other due to lower value discrimination in frequencies of the auditory system. According to Feldman & Grimes, (1985) “noise is an aperiodic acoustic signal, originating from the superposition of several vibration movements with different frequencies, which are unrelated to each other”. In general, noise can be defined as any unhealthy auditory sensation and/or as a non-periodic acoustic phenomenon without defined harmonic components, being treated by the World Health Organization (WHO), since 1980, as a public health problem. Noises can be classified, according to the variation in their intensity level over time, into: Continuous – noise that within a period of 5 minutes presents a variation of less than or equal to 6 dB (A) between its maximum and minimum values; Discontinuous – noise that within a period of 5 minutes presents a variation greater than 6 dB (A) between its maximum and minimum values; Constant – noise that does not present any level variation within a period of 5 minutes; Pure tone – noise consisting only of frequency; Impact or impulse noise – noise that appears in peaks of acoustic energy lasting less than one second and that repeats at intervals longer than one second. Considered one of the most harmful, it has intensities that vary above 100 dB. Noise can also be classified according to the generating source, as: Direct – the individual is close and in front of the source; Reflected – not close to the source, but close to the obstacle; Background – not directly inserted into the environment. Some known problems that reflect excessive exposure to noise are: hearing loss, acoustic trauma, temporary hearing loss, permanent hearing loss, tinnitus, recruitment, deterioration of speech discrimination, otalgia and extra-auditory effects. Therefore, controlling noise emissions in environments prone to exceeding the limits stipulated by legislation is extremely important. Considering the activities of the machines in the project's works, as well as the cement grinding activities to be carried out during the operation phase, the area in question requires attention and control with regard to the emission of high levels of noise.