Turning Heat Into Sound Into Electricity

WrongSizeGlass writes "Science Daily is reporting on work by physicists at the University of Utah who have developed small devices that turn heat into sound and then into electricity. 'We are converting waste heat to electricity in an efficient, simple way by using sound [...] It is a new source of renewable energy from waste heat.' They report that technology holds promise for changing waste heat into electricity, harnessing solar energy and cooling computers and radars."

Comments

Efficiency as opposed to thermoelectric?

[Anonymous Coward]

I just skimmed the article, but I didn't see mention of the efficiency of this process. What are the advantages to converting the heat to sound first, rather than directly to electricity via thermoelectric processes?