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The history of speech synthesizers: the first mechanical installations

Inanimate objects capable of speaking were featured in the legends of ancient civilizations. In Sumerian mythology, the god of war Ninurta had a magic mace that shared tactical advice in battle. The Scandinavians believed that Odin had bewitched the severed head of the once wise giant so that she could speak. But despite the popular image, the first attempts to implement speech synthesis at the technological level were made in the XVIII century. We tell you who did this.


Photo suanmoo / Unsplash

The first experiments in the Russian Empire


In 1779, the St. Petersburg Academy of Sciences announced an annual award for the creation of a mechanical device capable of emitting five long vowels: a, e, u, o, u . The winner was Danish professor of mechanics Christian Gottlieb Kratzenstein, who at that time was giving lectures at the universities of St. Petersburg.

Kratzenstein was in close relationship with Leonhard Euler, who studied the physical properties of sound waves. After consulting with a colleague, a Danish engineer developed a system of acoustic resonators that generated vowels using a pulsating air flow. This flow was created by vibrating metal tongues, playing the role of the vocal cords of a person.

Kratzenstein described the principles of his system in the book " Tentamen Resolvendi Problema ". Researches of the scientist had a serious impact both on the development of speech synthesizers and musical instruments. The freely slipping metal tongues , which the professor used to excite the resonators, later became the central part of the harmonics and button accordions.

After the presentation in St. Petersburg, the prototype of the Kratzenstein system was lost. However, in 2006, the German linguist Christian Corpiun was able to recreate it based on information in the Tentamen Resolvendi Problema. Today, a replica (p. 3) can be found at the Dresden Technical University, which houses one of the largest collections of audio devices.

Kempelen Mechanical Voice


Regardless of Kratzenstein, the Austrian inventor Wolfgang von Kempelen worked on a mechanical speech synthesis system . He presented the result of his labors in 1791.

His car modeled the human voice path. Special bellows supplied air to a metal tongue and excited a flexible resonator. The operator controlled his hand, changing the form and interrupting the flow of air, thereby modifying the sounds. According to Kempelen, the machine produced 19 distinct consonants and short phrases in several languages. However, due to the large number of moving parts it was difficult to control the instrument, and he "spoke" only in experienced hands. Here's how it worked:


The original version of von Kempelen’s machine has survived to this day. Until 1906, she was at the Vienna University of Music and Performing Arts. Then it passed into the hands of specialists from the German Museum in Munich, where it still stands.

The talking head of Joseph Faber


Wolfgang von Kempelen described the construction and operating principles of his machine in detail in the book Mechanismus der menschlichen Sprache nebst Beschreibung einer sprechenden Maschine. He hoped that other inventors would be able to improve the system for speech synthesis. And his experience was used by the Austrian mathematician Joseph Faber (Iosif Faber) to create a talking machine " Euphonia ."

Photo atlasobscura / PD / In the photo: Euphonia
The installation was a hybrid of Kempelen and piano. For entertainment, the inventor decided to design the resonator in the form of a human head. Fourteen keys made it possible to control the articulation of the jaw, lips and tongue. The role of the lungs and larynx was played by blacksmith bellows and a thin plate of ivory on a rubber lining.

The inventor took about 25 years to develop the system. He spent seven of them forcing the car to correctly pronounce the sound and . Faber made grandiose plans for Euphonia — for example, he dreamed of using the system to voice telegram texts. But she was destined to remain only a curious toy, since the talking head caused the effect of " sinister valley". People were not eager to place an unpleasant human-like object in their homes.

After the death of the inventor, the car went to his nephew, also Joseph Faber. As a mechanic by profession, he introduced a number of technical improvements into its design and continued to work as an uncle, demonstrating the system in different European countries.

He also came to Russia - in 1883 a “talking head” was shown at Kazan University. But Faber Jr. also failed to arouse great interest in the system.

The sounds extracted from the synthesizer were rude, monotonous and not always similar to real human speech. But despite the unsuccessful implementation in the form of a head, this mechanism is considered one of the most successful talking devices. He influenced the development of speech synthesizers in the 20th century. We will talk about the achievements of engineers of this era next time .


Additional reading from our Hi-Fi World:

History of audio technology: synthesizers and samplers.
Sound on wire: history of the telegraph.
Trautonium: German wave in the history of synthesizers.
Bobbiniki: a brief history of reel tape recorders.
Era of compact audio: history of Stereo 8 - cassettes with eight sound tracks.


At us on Habré: how sound affects health - from "noise hygiene" to good sleep and GTD .

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