Termination impedance of open-ended cylindrical tubes at high sound pressure level

Enhanced Sound Pressure Level by High Effective Index of Refraction and Impedance in an Acoustic Metamaterial Cavity

We design and experimentally demonstrate an acoustic metamaterial localization cavity which is used for sound pressure level (SPL) gain using double coiled up space like structures. This unique behavior occurs within a subwavelength cavity that is 1/10 th of the wavelength of the incident acoustic wave, which provides up to a 13 dB SPL gain. We show that the amplification results from the Fabry...

Sound pressure level generated by individual portable sound equipment.

INTRODUCTION The use of Personal Digital Audio Players can cause hearing injuries, as the sound is generated directly in the ear canal. It is believed that different types of headphones can cause different amplifications, since they cause changes in the volume and resonance of the ear canal according to their depth. OBJECTIVE This study aimed to determine the sound pressure to which young ind...

Waveguide Simulation of Non-Cylindrical Acoustic Tubes

Sound pressure level in a municipal preschool

AIM  To evaluate the sound pressure level to which preschool students are exposed. METHOD  This was a prospective, quantitative, nonexperimental, and descriptive study. To achieve the aim of the study we used an audio dosimeter. The sound pressure level (SPL) measurements were obtained for 2 age based classrooms. Preschool I and II. The measurements were obtained over 4 days in 8-hour session...

Charts for Estimating the Axial Shielding Factors for Triple-Shell Open-Ended Cylindrical Shields

Describing the shields with the number of shells greater than two differs from the previously done work in having a significant increase in the number of charts needed. To limit the number of charts, only the shields were examined that have the most-used exterior aspect ratio, namely, equal to 5. It was also assumed that all the shielding shells are made of the same material with an equal and r...