WHY are mammals’ inner ears coiled like a snail shell? One popular theory is that it simply allows the long organ to be packed into a small space, but now Daphne Manoussaki at Vanderbilt University in Nashville, Tennessee, and colleagues have come up with a different answer.
They say the shape improves hearing by amplifying sound vibrations, particularly for low frequencies (Physical Review Letters, DOI: 10.1103/PhysRevLett.96.088701). “The increasing winding along the tube causes the energy from sound waves to build up towards the outer wall of the spiral,” Manoussaki says.
The researchers liken this to the “whispering gallery” effect…
