Q. (See question 2805 above). Can one place a small piece of paper between the thumbs, and whistle on Shabbos?
A. Although we mentioned that it is permitted to whistle with one’s mouth on Shabbos, using any instrument is not. Placing a small piece of paper between the thumbs and blowing on it and thus creating a sound, may be tantamount to using an instrument.
Horav Shlomo Miller’s Shlit’a opinion is that the point is debatable and one should therefore avoid using this method for whistling.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller and Horav Aharon Miller Shlit’a