However, both appear to be extraordinarily insensitive and I'm wondering if I'm doing something wrong. I have adjusted the potentiometer on them more than ten turns which changes the output value (from 15 to 700) but doesn't appear to increase the sensitivity. I have to shout or whistle loudly for anything to register. This clearly isn't going to work for a long case clock which ticks quite loudly but nothing like as loudly as I can whistle. I also cannot work out whether the value is supposed to increase or fall as it tends to jump up and down on the rare occasions anything registers.
Has anyone else had any success using the KY-038? Is there a more sensitive alternative?