The attenuation of sound by absorption and conversion to other energy forms is a function of sound frequency and the properties of water.
We determined that attenuation of sound amplitude varies in a manner dependent on the average molecular weight through which the sound wave passes.
Earplugs (28 dB attenuation of sound pressure level; Aearo Ear TaperFit 2; Aearo Co). and headphones (30 dB attenuation of sound pressure level; Commander XG MRI Audio System, Resonance Technology inc).
But temperature isn't the only climatic factor affecting the attenuation of sound, the researchers note.
Global attenuation of sound pressure levels of up to 15 dB is realized.
Attenuation coefficient, sound speed and impedance ranged from 0.08 to 0.14 dB/cm at 1 MHz, 1546 to 1595 m/s and 1.58 to 1.68 Mrayl, respectively.
The acoustic pressures at both fundamental and harmonics decreased drastically as the liquid height was increased due to the attenuation of sound energy.
Its analysis has shown that rheological properties of the liquid essentially influence the speed and attenuation of sound in the waveguide.
The optimal attenuation of sound fields inside moving vehicles in cruise conditions by active acoustic control depends on the number and locations of acoustic secondary sources.
In presence of gas bubbles the variation of transmission time is not very regular while the relationship between attenuation of sound and phase hold-ups remained systematic.
