Personally, I feel it’s not the wood that matters. It comes down more to how the whistle is designed and how skilled the maker is at working the wood. There are enough examples of rosewood whistles that are terrific as well as those that are pretty terrible. I have had three Thin Weasel high D’s from Glenn Schultz - blackwood, cocobolo and yellowheart. They were all remarkably similar in sound and playing character. I have two of Paul Busman’s whistles - one rosewood and one in olivewood. Both play and sound quite similar. And that is what I think matters. How consistent is the maker in producing their instruments out of various timbers.
I personally do not think that a particular wood has a particular sound. Buy a delrin whistle of the same design from one of the several of the wooden whistles makers that also work in that polymer material and compare the results. The wood is merely a container for the vibrating air column. But wood does dictate certain practical dimensions and methods of manufacture versus metals and polymers. So there can be differences. But we all know the mythology of “timber timbre”. Don’t we?
Lots of timbers have the characteristics that will help make a good whistle - tight grain, high density, dimensional stability, etc.. Still other less capable woods can be used with a little help from coatings and stabilizing treatments. So there really isn’t much wood that can’t be made into a durable and playable whistle. I like woods with dramatic figure, color and grain such as snakewood, olivewood, acacia koa, cocobolo, kingwood, curly katalox, Brazilian tulipwood, etc., etc., etc.. Colors are nice too and it is surprising how many colors occur naturally in different woods - reds, greens, oranges, pinks, purples, grays and yellows. There are really too many nice woods to mention. There is literally no end to the variety. That is something about which I will always remain in awe.
For me wooden whistles are interesting because of the variety of color, grain and figure that is unique in every piece of wood. I have a lot of wooden whistles. But I do have more plastic, aluminum and brass whistles. But the allure of the wood far outstrips the practicality of the other materials. I decided a long time ago that the only way to fulfill the allure of timber whistles (and flutes) was to make them myself. It is not a simple thing to do either. I do enjoy the effort it takes. I really like turning a piece of wood from square to round and seeing what comes out in the wood.
Whistles, perhaps not exactly what we know as whistles here, have been made from wood for centuries if not for several millennium in many cultures around the globe. And while we do have the luxury of many other materials these days, I do not think that wooden whistles are anywhere near in danger of becoming a thing of the past.
Feadoggie