well… it’s been a disappointing week. on tuesday, a colleague dropped by and asked, since english is my first language, to explain the difference between “acoustic” and “acoustical”. i gave him the answer i thought was correct, but had doubts, and so we did some digging.

it turns out that something that makes a sound or is a characteristic of the sound itself is “acoustic” – as in “acoustic guitar”, “acoustic impedance”, “acoustic load”, “acoustic energy”

however, something that relates or pertains to acoustics, then you use “acoustical” – for example “acoustical engineer”, “acoustical society”, “acoustical measurement”

of course, given some thought, this makes sense. it’s an “electrical engineer” not an “electric engineer” – since it doesn’t require batteries.

seems i’ve been mis-using the terms for a while. sigh…