To add to the continuing attempt to suggest sighted bias doesn't exist or
is a natural product of the human perception process, consider:

http://www.sciencedaily.com/releases...0220074652.htm

In short, while different areas of the brain are used to interpret input
from the various senses, there is overlap in the areas such that sight can
influence sound perception. Seeing a yamaha and pass labs amp side by
side and doing sighted "tests" will trigger this overlap, make it
imposibble to know which amp is being used and the "tests" do as well as
random choices; just as the now famious test demonstrated.