Both these popular methods are used to analyze sound and better understand the acoustic phenomenon.
From the en.wikipedia.org
This energy tends to dissipate rapidly, but when SAWs reach a frequency of around 10MHz in water-based fluids, they give rise to an unusual phenomenon called acoustic streaming.
From the economist.com
This year's other big phenomenon, Ed Sheeran, on the face of it an old-fashioned MOR acoustic singer-songwriter, began 2011 releasing an album of collaborations with UK rappers.