AFTERTHOUGHT: I’m sure the reason the vent opening of the STUDY-32 (and other melodicas) is tiny is to keep the seal as tight as possible. You don’t want a leaky melodica. When you blow into it with neither keys nor the vent button depressed, no air should escape. In theory, at least. The design and flimsy construction of the STUDY-32 are not conducive to a very good seal, in any case. I didn’t think to check its seal before operating on it, mainly because it was so easy to play that a possible seal issue didn’t occur to me. I did think to check the seal after the operation, and it is not very good. However, I don’t notice any difference at all in playing the melodica. So for whatever reason the STUDY-32 doesn’t need a very tight seal. But when I try this procedure on another melodica I’ll be more careful and will start out with a more modest enlargement of the vent hole. Also, any kind of ridging around the edge of the inside of the hole could create a leakage problem with some vent mechanism designs. Although there may appear to be some ridging in these photos, I carefully scraped what was there off.