Editing The Conversation (section)

===Inspiration===
According to surveillance technology expert Martin Kaiser, his colleagues consider him to the inspiration for the character of Harry Caul. Kaiser also says that he served as a technical consultant on the film, though he was not listed in the credits.<ref>{{cite book |last1=Kaiser |first1=Martin L. |last2=Stokes |first2=Robert S. |title=Odyssey of an eavesdropper: my life in electronic countermeasures and my battle against the FBI |date=2005 |publisher=Carroll & Graf ; Distributed by Publishers Group West |location=New York : [Berkeley, Calif] |isbn=9780786715466 |pages=x |edition=1st Carroll & Graf |url=https://archive.org/details/isbn_9780786715466/ |access-date=7 April 2025 |quote=I was considered by my colleagues to be the inspiration for Harry Caul, the paranoid eavesdropping expert played by Gene Hackman in Francis Ford Coppola’s 1974 post-Watergate drama, The Conversation}}</ref><ref>{{cite web |url=http://www.martykaiser.com/odyssey2.htm |title=Odyssey of an Eavesdropper |first1=Martin |last1=Kaiser |first2=Bob |last2=Stokes |website=Martykaiser.com |access-date=September 2, 2017}}</ref> According to Kaiser, the final scene of the film—in which Caul is convinced he is being eavesdropped in his apartment, cannot find the listening device, and consoles himself by playing his saxophone—was inspired by the passive [[covert listening device]]s created by [[Léon Theremin]], such as [[The Thing (listening device)|the Great Seal bug]]. "He couldn't find out where [the bug] was because it was the instrument itself."<ref>{{cite web |url=https://www.youtube.com/watch?v=bb-bdHGBcUY#t=45m00s | archive-url=https://ghostarchive.org/varchive/youtube/20211118/bb-bdHGBcUY| archive-date=November 18, 2021 | url-status=live|title=The Last HOPE: TSCM – A Brief Primer on Electronic Surveillance and 'Bug' Detection (Complete) |publisher=GBPPR2 |date=September 22, 2011 |access-date=May 22, 2017 |via=YouTube}}{{cbignore}}</ref>

Coppola also based Caul on the protagonist of [[Hermann Hesse|Herman Hesse]]'s 1927 novel ''[[Steppenwolf (novel)|Steppenwolf]]'', Harry Haller, a "total cipher" who lives alone in a boarding house. Coppola also made Caul religious, including a [[Confession (religion)|confession]] scene; Coppola has said that the practice of confession is "one of the earliest forms of the invasion of privacy—earliest forms of surveillance."<ref>{{Cite web|date=October 2, 2019|last = Suton |first = Koraljka |title='The Conversation': Francis Ford Coppola's Paranoia-Ridden Tale of Surveillance, Guilt and Isolation|url=https://cinephiliabeyond.org/the-conversation/|access-date=June 11, 2022 |website=Cinephilia & Beyond | archive-url = https://web.archive.org/web/20191230123341/https://cinephiliabeyond.org/the-conversation/| archive-date = December 30, 2019 |language=en-US}}</ref>

Caul was also inspired by Karl Schnazer; a private investigator and occasional actor who appeared in Coppola's early films ''[[Tonight for Sure]]'' and ''[[Dementia 13]]''.<ref name=":0">{{Cite web |last=Galloway |first=Stephen |date=2014-06-03 |title=Karl Schanzer, Who Inspired Coppola's 'The Conversation,' Dies at 81 |url=https://www.hollywoodreporter.com/movies/movie-news/karl-schanzer-who-inspired-coppola-708829/ |access-date=2025-01-25 |website=The Hollywood Reporter |language=en-US}}</ref> Schnazer recounted to Coppola an incident where a man he had tailed for months failed to recognize him at a party, which later inspired a sequence in the film.<ref name=":0" />