Can you expand and maybe source that comment. "Initially funded" to me suggests that the R&D was funded by people/companies for the purpose of carrying pornography.
"Popularised by" is often suggested, or even "first exploited commercially for" - either of these seem far more likely. I just can't see Daguerre, or whoever (Wedgewood, Fox-Talbot, ..), getting pay-checks from people/companies that want to publish porn?
I'm not saying, yet, that you're wrong - history is often surprising.
By wire recordings you mean the audio recordings on wires that predate reel-to-reel and such. Are there existing audio porn recordings from the 1890s? It seems strange with the cost of the tech that anyone would even want it as a recording when the people who could afford it, given the massive difference in income and the availability of prostitutes, could order a live rendition. Stranger things have happened though.
Telegraph? Morse or semaphore porn, ... I'd have thought that was really an exception to Rule 34!?
That would be a major market for this technology.