[The most recent 'Error' page in a series which documents errors in the 9/11 literature. One of the goals of 911review.com is to highlight these errors and improve the quality of analysis in the community of skeptics.]
The idea that phone calls from passengers on the targeted flights were fake and actually created with voice-morphing technology has been promoted by several "no Boeing" advocates and in particular detail by author David Ray Griffin in his numerous books, talks, interviews, and essays.
The case for the 'fake phone calls theory' as articulated by Griffin has become ever more nuanced and complex as government and airline disclosures have undermined the simplicity of the original set of claims surrounding the calls, and other researchers have pointed out flaws in that case. However, the theory remains rooted in the premise, seemingly calculated to be offensive attack survivors, that the last voices heard from victims on the planes were faked.