The History of Simultaneous Interpreting Equipment

Simultaneous interpreting is a popular interpreting modality, used in conferences, workplace training sessions, and legal or government settings. In the case of simultaneous interpreting, the interpreter performs a 3-part simultaneous process:

  • listening to the source language speaker
  • mentally converting the message into the target language
  • interpreting in the target language to 3rd party/audience

This is done simultaneously while the speaker continues to deliver their speech, which is why simultaneous interpreting requires such a high level of skills and immense concentration.

In this post, we will reveal a timeline of simultaneous interpretation (SI) equipment, and how it is used in the world today. We’ll also highlight four individuals who were crucial to the emergence of SI equipment.

Early Beginnings

The concept of simultaneous interpretation has ancient origins, relating to the chuchotage (French for “whispering”) which refers to the primitive/natural form of interpreting where an individual would use crouching posture and communicate by whispers and murmuring. Today, whispering form of simultaneous interpreting is still common and can be performed without equipment. However, it can work only with a very small group with the interpreter standing or sitting next to the person in need of interpreting. It’s not feasible for this modality to be utilized with more than 2 recipients, otherwise, they won’t be able to hear the interpreter.

Simultaneous Interpretation Equipment

Today, simultaneous interpretation equipment is used in a variety of ways that include: business negotiations, conferences, expo shows, court hearings, tours, group meetings, and more. All of the above requires simultaneous interpreting to be used. There are two major types of equipment: portable and stationary.

Portable equipment is generally used for tours, court hearings, small group discussions and other settings where overall group size and their proximity to each other is manageable. The equipment consists of receivers worn by the listeners and a transmitter with a microphone used by the interpreter.

Stationary equipment is used to achieve the highest level of communication in large group settings such as conferences, auditoriums and other events with a large number of participants requiring interpretation services.

In most cases, simultaneous interpreting equipment includes:

  • Microphone or headset with microphone, these are solely used between the source language speaker and interpreter for clear communication
  • Soundproof interpreting booth that gives the interpreter a noise free area to concentrate.
  • Wireless headsets for 3rd party or audience to hear a clear rendition from the interpreter

For a more detailed breakdown of the different types of simultaneous interpreting equipment available for events, check out our blog, “An Introduction to Interpreting Equipment Rental.”



Four Pioneers of Simultaneous Interpreting

1) Edward Filene and Alan Gordon Finlay: American businessman and philanthropist, Filene first mentioned the concept of simultaneous interpretation in 1925. Filene was not an engineer so he called upon the help of a British electrical engineer Alan Gordon Finlay.

Together with Alan Gordon Finlay, they co-designed the “Filene-Finlay simultaneous translator" which utilized phone equipment and marked the begining of telephonic interpreting. They later patented and commercialized the device with success and sold it to IBM under the patent name "Hushaphone Filene-Finlay system. 

2) Andre Kaminker was a highly influencial figure in language interpretation. In 1934 he simultaneously interpreted Hitler’s speech at Nuremberg for French radio and was one of the first individuals to perform simultaneous interpretation as we know it today: live from an audio feed without using a pre-translated text. The Nuremberg Trials (1945-1946) are remembered as one of the first significant uses of simultaneous interpreting and is often credited to being the official birthdate of SI equipment. 

3) Leon Dostert was staff officer and interpreter for Gen. Eisenhower. He was called upon to find a practical solution to the language barrier. He assembled teams of interpreters for the Nuremberg trials after WWII. It was the first large scale use of simultaneous interpretation equipment. Later in life, he was an advocate for using simultaneous interpretation equipment at the United Nations.


As the world becomes more connected, the importance of simultaneous interpretation will continue to grow. Thanks to the innovation of Edward Filene and Alan Gordon Finlay in the 1920’s, many individuals throughout history were able to overcome language barriers. Almost 100 years later, simultaneous interpretation equipment is still being used for business & government conferences, tours, and other settings. As long as language barriers are present in society, simultaneous interpretation equipment will be needed.