To fulfil the airport safety requirements as stated in International Civil Aviation Organization document, ICAO 9137-3 AN part 3 – Airport Services Manual, Wildlife control and reduction, especially the bird stike control programme, the Sam Ratulangi International Airport is decided to apply the auditory method to control the birds in aerodrome area. Study on this need have been carried out using the sound energy approach, more specifically on inverse square law theory in free field. The theory said that by doubling the distance between the speaker and the sound level meter will decrease in sound pressure level of around 6 dB. From the field measurement results, the measured sound pressure level were 85 dB and 79 dB at the distance of 50 m and 100 m from the speaker. Both levels and distance were used in trials of repelling birds at 1600 Hz to 3150 Hz in frequencies. The use of long range acoustic device, LRAD speakers, that genereate 156 dB at a distance of 1 m in front of the speaker can effectively reach longer distances.
A large number of industrial needs to the sound level meter (SLM) calibration has encouraged the laboratory to develop a qualified calibration system. As one of the SLM calibration methods required by the standard, the coupler method is considered as the most convenient to be implemented, especially for the secondary laboratory. Therefore, the aim of this work is to compare the SLM calibration for the frequency weighting parameter by this method using the instrument standards that comprise of a multifunction acoustic calibrator and a working standard of pressure microphone (WS2-P Microphone). Moreover, the result of frequency weighting calibration using these standards, therefore, is compared to the reference value required by IEC 61672-1. From the result, the deviation values of these standards are obtained relative to the reference. At the low to middle frequencies, the deviation values are slight relatively, while at the higher frequency, it tends to bigger. In addition, these methods also support the development system of noise dosimeter and sound level meter calibration that still under research through the scheme of Incentive Research Program for the National Innovation System in 2020.
Laminated glass is one type of glass that is commonly used for sound insulation (walls or doors). Tests related to the ability of insulating glass in Indonesia are still very rare. One of the places to do this test is the SNSU BSN Lab. This lab has a function to perform sound insulation level measurements commonly known as Sound Transmission Class (STC) and maintain to trace ability of acoustic measurements. This paper aims to describe the characteristics of Sound Transmission Loss (STL) of 12mm laminated tempered glass. The sample measurement method refers to ISO 10140-1 using two chambers (source and receiver room). Based on the results of the study, it was found that the laminated tempered glass sample was not good at reducing sound at low frequencies and tended to be good at high frequencies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.