Editing Wolfgang von Kempelen's Speaking Machine (1769) (section)

== Impact ==
Von Kempelen's travail was not for naught and his impact far from nil.<ref name=":2">Schroeder, Manfred R. “A Brief History of Synthetic Speech.” ''Speech Communication'' 13, no. 1–2 (October 1993): 231–37. [https://doi.org/10.1016/0167-6393(93)90074-U. https://doi.org/10.1016/0167-6393(93)90074-U.]</ref> Kempelen's speaking machine together with the book "Mechanismus der menschlichen Sprache" ("Mechanism of Human Speech and Language") he published  in 1791 in which he described his observations on human speech production and his experiments with his speaking machine had a profound and multifaceted impact on the development of new ideas in linguistic research and advancements in audio engineering.

==== 1. Contributions to linguistic research： ====
While before Von Kempelen the larynx was considered central to speech production, his simple and successful demonstration drew the attention of 19th-century scientists to the vocal tract, the cavity between the glottis and the lips, as the main site of acoustic articulation.<ref name=":2" /> In his book, he classifies the vowels according to her width of the lip channel giving a ranking of A >E>I>0>U and the width of the so called tongue channel that can be interpreted as horizontal tongue position. Although Kempelen isn't very explicit here, the observation clearly resembles the perceptual analysis of the second formant in whispered vowels described a century before by Reyher (1679) and the vowel tunes of [[wikipedia:Hermann_von_Helmholtz|von Helmholtz]] (1862). <ref name=":3">Pompino-Marschall, Bernd. “Von Kempelen’s Contribution to the Theory of Acoustic Articulation,” n.d.</ref>This innovative vowel classification (classifying vowels based on characteristics like the width of the lip channel and tongue channel) represented a novel approach to the study of speech sound physical properties.

==== 2. Development of Speech Synthesis and Audio Engineering： ====
Development of Speech Synthesis: Kempelen's research findings represented a crucial step in the development of speech synthesis. His insights into the resonating properties of the vocal tract and the impact of tube width on vowel production provided the foundational knowledge that subsequent researchers needed to simulate human speech mechanically.

Influence on Later Innovators: Later innovators built upon Kempelen's ideas, gained insights into resonating properties and developed theories of multiple resonance (the amplification or reinforcement of specific sounds produced by the vocal tract). [[wikipedia:Christian_Gottlieb_Kratzenstein|Christian Kratzenstein]], who made notable contributions to the study of speech and acoustics in 1779 and made early attemps at [[Mechanical synthesis|mechanical speech synthesis]], built upon the groundwork laid by Kempelen. In 1830, it was [[wikipedia:Robert_Willis_(engineer)|Willis]], starting from the ideas of Kratzenstein and von Kempelen, who first gained resonable insight in the resonationg propgerties of neutral tubes that would be able to give the illusion of different vowels. And in 1838 [[wikipedia:Charles_Wheatstone|Charles Wheatstone]] constructed his famous version of von Kempelen's speaking machine. It was a bit more complicated and was capable to produce vowels and most of the consonant sounds. Some sound combinations and even full words were also possible to produce.<ref>[http://research.spa.aalto.fi/publications/theses/lemmetty_mst/chap2.html Lemmetty, Sami. “Review of Speech Synthesis Technology,” n.d.]</ref>Inspirations in research and experiments with mechanical and semi-electrical analogs of vocal system  in speech synthesis technologies were directly influenced by Kempelen's early work, making it a key milestone in the history of speech technology.

Kempelen's Speaking Machine represented an early mechanical approach to imitating speech sounds, and a few decades later the [[Voder|Voder from the Bell Telephone Laboratory]] was a pioneering electronic device that introduced new possibilities in generating speech-like sounds. Kempelen's Speaking Machine and the Bell Telephone Laboratory's Voder were foundational in the history of speech synthesis, paving the way for more advanced and realistic speech synthesis technologies that followed in the decades and centuries thereafter.