The latest Flute Talk magazine has an article of interest to singers, because it deals with listening to one’s body to determine if correct tone is being produced.
Author and flutist Jessica Quiñones Discovered this while working with one of her students, who’s aurally challenged. However, the student could very quickly identify and remember specific body/muscle positions that Quiñones identified as good tone. The student was then able to reproduce them easily. Sorry the article’s not available online.