This post is a general explanation about simultaneous interpretation equipment for end users.

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What is Simultaneous Interpreting:

Simultaneous interpreting (or simultaneous interpretation) is one of the most complex types of language use. Interpreters are using highly specialized wireless equipment and are working in a soundproof cabin called “simultaneous interpreting booth.”

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Brief History of Simultaneous Interpreting Equipment:

Attempts to design simultaneous interpreting equipment started in the s with Edward Filene and Alan Gordon Finlay. The system was called “the Filene-Finlay simultaneous translator” and was used to read texts that had already been translated before the event.

No one thought at that time that “live” simultaneous interpretation was possible.

During the Nuremburg Trials after WWII we see simultaneous interpreting equipment that is more similar to what we have today.

A lot of credit in perfecting the equipment goes to the United Nations, where simultaneous interpretation was introduced (with some resistance at first) after the World War II.

Simultaneous Interpreting Equipment Today:

Today the majority of conferences is in simultaneous interpretation mode, and manufacturers of simultaneous interpretation equipment abound.

A note has to be made that like in any market quality of design and construction varies greatly and – caveat emptor – cheap solutions are not too reliable.

Utmost care has to be taken when selecting your simultaneous interpretation equipment provider: best if it is a company that specializes in such equipment and not just an audiovisual company or a videographer.

Professional conference interpretation and translation agencies will either have their own equipment or have a working relationship with such specialized companies.

It is best if you purchase conference interpreter services and rent simultaneous interpretation equipment from the same company instead of shopping around. It is one of the scenarios where one stop shopping for language services works!

 What Simultaneous interpretation Equipment Setups Exist?

Generally only 3:

Permanent installations

These are simultaneous interpretation systems permanently built into conference facilities – think the United Nations, the European Parliament or a major conference center.

Booths are actually small rooms with doors where interpreters work. It is the most comfortable and convenient setup, but, for obvious reasons, it is not very mobile.

Portable/mobile setups

Most hotels and other venues do not have permanent installations. Instead, portable (mobile) booths have to be brought in and installed before the conference.

It must always be booths for at least 2 interpreters per booth per language and at some major conferences 3 interpreters per booth per language are engaged.

Portable booths have the same features as stationary ones such as lighting and ventilation, but the equipment is highly mobile.

Whispering Equipment:

It is a portable set consisting of a wireless handheld transmitter and standard wireless receivers. While good for tours or if the participants must move around a lot, it is not suitable for a standard conference in one room.    

What equipment is inside the simultaneous interpretation booth?

Simultaneous Interpreter Console

Simultaneous interpreter console is an electronic box with audio connections for the interpreter headset and the interpreter microphone. Because more than one interpreter is engaged, there must be as many headsets and microphones as there are interpreters.

The console has a number of switches to switch between languages, adjust headset volume and bass/treble, as well as turn the microphone off temporarily (mute button of cough cut.)  

Interpreter Headset:

Each interpreter must have his own her own headset provided to them by the audio technician.

Many professional conference interpreters own their headsets they travel with, and headset manufacturers have headset models specifically designed for best voice reproduction and for simultaneous interpretation.

Headsets must be binaural i.e. the interpreter must be able to hear the original speech with both ears.

Interpreter Microphones:

There are 3 major options for interpreter microphones:

Integrated into a headset. The microphone is attached to the headset with a special flexible gooseneck arm. It is the best and the most convenient option. When moving your head, the distance between the interpreter mouth and the microphone does not change.

An interpreter microphone integrated into a console.

It is a less convenient but still very legitimate option. The top surface of the interpreter console has a dedicated microphone connector (usually XLR) the gooseneck microphone is inserted into.          

Standalone tabletop microphone.

It is the least convenient option. A separate microphone in placed on the interpreter desk and connected to the console with a cable.

The danger here is that the interpreter may accidentally move the microphone when it is “hot” i.e. when it is on. The resulting sound may be very unpleasant for the delegates to hear.

In terms of microphone safety, headset microphones are certainly best!  

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Other equipment in the Booth:

Other equipment in a simultaneous interpretation booth must include appropriate lighting, ventilation fans, chairs and may also include internet and power connections.

Wireless receivers for delegates:

The audio feed from the speakers’ microphones is transmitted into interpreters’ headsets. The simultaneous interpretation interpreters produce is fed into a wireless transmitter and into receivers and headsets each delegate has.

A few points to remember:

-Always get your receivers and headsets before a conference starts, otherwise, you may have to do it in the middle of a presentation.

-For large conferences some conference organizers will issue you a receiver only in exchange for your identification document they will keep for the duration of the day or of the conference. Have an alternative form of ID on you in case if you need to use it during the event.

-When you turn on your headset for the first time, never use the full volume. While simultaneous interpreters are professionals and know how to use microphones, accidents happen and loud sounds may damage your hearing.  

-Same is true for interpreters. You must never tap or bang a live microphone – it is a serious health hazard for those who are listening to you i.e. for the conference interpreters.

-Know what channel your languages are on. Usually channels are numbered and the channel allocation will either be posted on simultaneous interpretation booths or announced before the conference.   

-A fully charged receiver should be operational without any issues for an entire day but sometimes batteries in simultaneous interpretation receivers discharge and sound quality deteriorates. Report it to the audio technican who will give you a new receiver.

 -To prevent microphone feedback never place your headphones next to a live microphone.      

Are there standards for simultaneous interpretation equipment?

Yes and they are rather detailed.

ISO “Simultaneous interpreting – Permanent booths – Requirements” covers the built-in installations, and ISO “Simultaneous interpreting – Mobile booths – Requirements” covers portable equipment.

There are other guidelines and standards by other bodies, such as  ISO/FDIS “Simultaneous interpreting — Equipment – Requirements” or ASTM F: Standard Guide for Language Interpreting Services.

If you are interested in this topic, see the Further Reading section at the bottom of this page.  

Who is the best simultaneous equipment manufacturer?

While there are many manufacturers, we think that Bosch interpreter consoles remain the Golden Standard. Various knockoff consoles exist but they do not seem to provide good user experience for interpreters in terms of user friendliness and sound quality.     

Using the highest quality interpretation equipment is in your best interests as an end user. Critical applications such as simultaneous interpretation require professional grade audio equipment and trained technicians too.        

Further reading and sources:

Does ISO Certification Mean Better Quality from a Translation Agency?

All about Simultaneous Interpretation – FAQ

Guidelines for Organizers, Participants and Chairs of Bilingual and Multilingual Meetings

Client Provided Simultaneous Interpretation Equipment (based on AIIC recommendations and common practices).

Off Site Links:

Alan Gordon Finlay and the Telephonic Interpretation System

On Comintern and Hush-a-: Early history of simultaneous interpretation equipment

6 Major Types of Interpreting

As stated in a previous blog (What is the Difference Between Translation and Interpreting?), interpreting is the real-time, spoken form of translation that facilitates seamless cross-language communication. Unlike written translation, interpreting involves conveying a speaker’s message aloud in another language, ensuring immediate understanding. Depending on the context, interpreting can take various forms to meet specific needs. Below, we outline the six major types of interpreting: simultaneous, consecutive, escort/travel, whisper, scheduled , and on-demand interpreting.

1. Simultaneous Interpreting

In simultaneous interpreting, the interpreter listens to a speaker while translating their words into the target language in real time. Despite the name, interpreters cannot begin speaking until they grasp the sentence’s overall meaning.

While listening to the speaker’s current words, simultaneous interpreters process and recall phrases spoken 5–10 seconds earlier, delivering an accurate translation without paraphrasing. This method is essential for large meetings, conferences, and trade shows—much like interpreting at the United Nations. Typically, interpreters work from a booth, wearing headphones and speaking into a microphone.

Simultaneous interpreters must think quickly and make split-second decisions. They have no time to debate word choices or search for the perfect idiom. Any hesitation risks losing key words—or even entire ideas—from the speaker’s message.

2. Consecutive Interpreting

During consecutive interpreting, the speaker pauses every 1–5 minutes—typically at the end of a complete thought—allowing the interpreter to translate their message into the target language.

This back-and-forth style of interpreting is common in smaller business meetings and courtroom proceedings, such as witness testimonies. Since speakers take turns, interpreters must accurately convey each message without losing key details.

Strong note-taking skills are essential in consecutive interpreting, as few people can retain and recall an entire paragraph after hearing it only once.

3. Escort/Travel Interpreting

Escort/travel interpreters serve as both language experts and personal assistants, helping clients navigate business trips or travel experiences. They may accompany clients to a single meeting or multiple engagements, ensuring smooth communication every step of the way.

Beyond interpreting, these professionals act as cultural liaisons, handling everything from ordering meals to facilitating high-stakes business negotiations. Their role extends far beyond language—they bridge cultural gaps and help clients build successful international relationships.

4. Whisper Interpreting

Whisper interpreting works like simultaneous interpreting, but without headsets or microphones. Instead, the interpreter sits next to the individual or group needing interpretation and whispers or speaks softly in the target language. This method puts extra strain on the interpreter’s voice.

Businesses often use whisper interpreting for meetings when only one participant needs translation. It’s also common in courtrooms, where someone seated at the back may need interpretation to follow the proceedings.

5. Scheduled Interpreting (OPI or Over-the- Interpretation)

Scheduled interpreting (also called OPI or Over-the- Interpretation) can be either simultaneous or consecutive. This form of interpreting is performed during an established appointment where the interpreter does not see both parties in person, but executes the interpreting via .

If the participants of a call are content to hear only the voice of the interpreter, interpreting can be conducted in a simultaneous mode; otherwise interpreting should be conducted consecutively.

If the interpreter does not see the speakers and has no access to extra-linguistic clues to the speaker’s meaning and context, the accuracy of simultaneous interpreting may be significantly lower than for consecutive over-the- Interpreting. Most generally, interpreting is conducted consecutively. Next we’ll outline the last of our six types of interpreting.

6. On-Demand Interpreting

On-Demand Interpreting helps individuals and organizations break language barriers instantly. To access this service, a caller selects the required language pair and connects with a professional interpreter. The interpreter then joins the conversation and facilitates real-time communication between both parties.

Customer service call centers, companies, organizations, pharmacies, and medical and legal institutions rely on On-Demand Interpreting to communicate with limited English proficiency (LEP) individuals. This service provides instant access to interpreters whenever needed.

One key advantage of On-Demand Interpreting is its rapid availability, connecting users with an interpreter within minutes. However, because the interpreter joins the conversation without prior context, they may lack essential background information, which can impact the accuracy and effectiveness of the interpretation.

What To Look For In Interpreting

No matter what type of interpreting you need, choosing the right interpreter requires more than just experience—it demands deep expertise in the subject matter. A skilled interpreter must listen intently, think quickly, and confidently deliver messages in another language. They must also excel in public speaking and instantly adapt idioms, colloquialisms, and culturally specific references into statements the audience will understand.

What types of interpreting have you had experience with? What tips do you have when looking for interpreters? Please share your thoughts in the comments section below.

To learn more about Language Scientific‘s different types of interpreting services click here.