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Accurate measurement of unsteady pressure fluctuations along a surface requires experimental set up with high spacing resolution and high frequency domain. Therefore, in recent decades extensive studies have been conducted on remote microphone approach. In this method, instead of using flash mounted sensors, they installed remotely and connected to the model surface through one or several continuously connected tubes. Surface pressure fluctuations will travel within the tubing in the form of sound waves and they will be measured when passing over the remote pressure sensor, mounted perpendicular to the tubing. In the present study, an analytical solution of sound waves propagation inside the rigid tubes is used for modelling of the remote microphone system and to investigate the effects of its parameters on dynamic response. In order to verify the accuracy of proposed modeling, the dynamic response of a typical remote microphone has been obtained through experimental calibration. Comparing the analytical and experimental results indicates high accuracy of the analytical modeling. Results show that changes in tubing diameter leads to occurrence of resonance and creating harmonics in two frequency regions. The amplitude of low-frequency harmonics depends on the length of the damping duct and decreases with increasing of its length. Instead, the amplitude and frequency of high-frequency harmonics depend on the length of the first tube and they decrease with the increase of first tube length. Also, Increase of the first and second tube lengths lead to an increase in phase of dynamic response of the remote microphone system.

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Due to lower cost compared to field measurement, simulation of sound propagation is considerably favorable for acoustic researchers. One of most optimized methods in this regard is PE (paraboloic Equation), which gives detailed low cost results especially in the low and mid frequencies. On the other hand, most of the human interaction with the water bodies are in the so called shallow water region, where PE is the most common method of acoustic simulation. In this study, effects of environmental parameters on transmission loss are investigated in the range of the scale of few tens of kilometers. The results show subsurface flows and sound speed profile variations in the course of the range, have the least effects and bottom properties, specifically the attenuation factor, are the most effective parameter in the low frequency sound propagation. On the other side, in the range of higher frequencies (more than 1000 Hz), seasonal variation of sound speed profile has the most efficient effect