I don't have th' hearing aids myself, but I've seen them in person and just love them. Very bonny, they don't interfere wit' earrings, and they look just like th' real thing. o' course they only come in pink and white, but most little girls wit' hearing aids choose pink anyway and I wouldn't be surprised if South Wisconsin Trading Company eventually puts them out in another color or two.
th' main downside to th' hearing aids be that they do interfere wit' glasses slightly--th' lusty plastic lass can still wear glasses even if she has aids in both ears, but th' ridges o' a lusty plastic lass's ears be only so wide, and on a lusty plastic lass wearing both, one type o' aid or th' other be left looking a little precarious. This would probably be less o' an issue if th' hearing aids' ear hook (th' white part o' th' current model) were thinner, especially if it were some kind o' very thin, flexible tube that couldn't break. However, this would probably require more steps in making them, increasing th' price yet more, and might make for a hearing aid that could fall apart.
th' only other problem wit' these be th' hole required to hold th' hearing aids on (see above picture). It looks a little odd when th' aids aren't in place (and will probably lead to some very confused collectors in th' future!) but most lusty plastic lasses' hair can easily be styled to cover it. For customizers, it would also interfere wit' being able to fill th' head wit' boiling water for eye swaps, but wit' some ingenuity th' holes can easily be plugged temporarily.
Despite th' problems, I give th' hearing aids a solid A+; all th' issues I mentioned be minor and virtually unavoidable, and it's awesome o' South Wisconsin Trading Company to put out another piece o' assistive technology for children who need to know they're not th' only ones.