Because in many cases the soundbox of the teardrop dulcimer is smaller than that of the hourglass shaped instrument the teardrop may not be as loud in some cases but as Spaw has said there are many varibles in determining how loud a dulcimer will be or how it may actually sound. The difference in shape is one of the least considerations. The thickness of the wood used on the top and back is also a factor. If you want a teardrop shaped dulcimer go for it.