THE BAT WHISPERS, like THE CAT AND THE CANARY, is an Old Dark House standard of the 1920s stage. I did not find it as engaging as THE CAT AND THE CANARY as entertainment, but it has distinct qualities which made it a wonderful experience, nonetheless.
One notable aspect of THE BAT WHISPERS is that it was filmed twice, the second version being in a then-experimental 65mm widescreen process. That's the version I watched. (Both versions are on the DVD.) It was a treat to see an early talky in 2:1. I don't know if I would have liked the format to have caught on or not - its success might have meant the loss of a couple of decades of artful cinematography designed for the Academy ratio. On the other hand, I love widescreen black and white.
THE BAT WHISPERS makes use of an abundance of inventive camera moves and model work in the transitional scenes, all of them well up to the standards of the best effects work of the silent era. Those come to a jarring halt for the dialogue scenes, which are much more stage-like, for the most part recorded with a stationary camera at medium range.
Although the schizoid nature of early sound films, lurching as some do between dynamic silent-style images and torpid microphone-friendly stationary dialogue scenes, is bemoaned by some, in the case of THE BAT WHISPERS, the dialogue scenes are wonderful documentary evidence of the source material's stage origins. You really get the sense during the dialogue scenes that you are watching a filmed record of a 1920s-era Broadway production. This is not only due to the relatively immobile camera, but particularly to the inflections and mannerisms of the cast. The Marx Brothers' first feature film THE COCONUTS gives you that same feeling. It is a rare treat to have such a window onto the past.