Our survey of the literature of the field of coin-tapping
test technology, the commercial products now on the market,
the instruments being used in key applications (aircraft
skins, boat hulls), and our own experimental results
all tend to support our working hypothesis that both microphones
and accelerometers have their separate valid roles
as instrumentation suitable for automating defect detection.
Further more, our research results show that by force
and sound measurement sensor fusion it is possible to
make “the whole greater than the sum of the parts”.