I want to know the answer to the following question:
The Volta lab improved the phonograph by replacing tinfoil with what substance?
All the background I'm provided with is that "The laboratory was also the site where he and his associate invented his "proudest achievement", "the photophone", the "optical telephone" which presaged fibre optical telecommunications, while the Volta Bureau would later evolve into the Alexander Graham Bell Association for the Deaf and Hard of Hearing (the AG Bell), a leading center for the research and pedagogy of deafness.". Is that enough to answer the question?
Answer: no