If an electric guitar have tremolo arm, floyd rose, or bigsby for doing vibrato sound. Is there anything (or tool) that can make vibrato sound in an acoustic guitar. Other than manually pullback the neck.
There is indeed!(at 1m46s)
I don't believe they're widely manufactured though, not from what I could find
Some of the Bigsby vibs will do the job.Particularly those designed for semis. They may be kinder to an acoustic guitar because they attach to the part of the guitar where the knob is for the strap, rather than on the belly itself. Watching the above video, it was difficult to tell whether the soundboard was being moved as the arm worked, or whether it was the reflection from the moving guitar, but I guess there will be a fair bit of extra stress at the bridge, that may need to see the inside beefing up. As the Bigsby needs only fittings on the end of the guitar, it could be removed without much evidence being left. Not so with Floyd-Rose type !
I think that both of Alexander Troup and Tim's answer are right. Because I can't pick both as an answers, I'll put here:
Well, thank you for your answers, I appreciate that.