Pitter-patter patterns.Pitter-patter patterns Rain falling on ocean surfaces generates characteristic noises that alter the spectrum of sounds usually encountered underwater (SN: 1/4/86, p.4). Now H.C. Pumphrey of the University of Mississippi The University of Mississippi, also known as Ole Miss, is a public, coeducational research university located in Oxford, Mississippi. Founded in 1848, the school is composed of the main campus in Oxford and three branch campuses located in Booneville, Tupelo, and Southaven. in University offers an explanation for how this noise is produced. He suggests that the noise is created by oscillations oscillations See Cortical oscillations. of bubbles generated by the impact of raindrops of a certain size. Pumphrey first studied the sound produced by a single drop striking a liquid surface. He found that the sound consisted of a sharp spike emitted when the drop first strikes the surface and then a decaying wave emitted when an air bubble is formed. By gently spraying water onto a large tank, he found that he could produce a noise spectrum similar to that observed for ocean rainfall. The addition of a surfactant Surfactant Definition Surfactant is a complex naturally occurring substance made of six lipids (fats) and four proteins that is produced in the lungs. It can also be manufactured synthetically. to lower the water's surface tension stopped bubble production, and the main spectral spectral /spec·tral/ (spek´tral) pertaining to a spectrum; performed by means of a spectrum. spec·tral adj. Of, relating to, or produced by a spectrum. peak seen in typical rainfall noise disappeared. |
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