iProbe Knowledge Base

The Beginner's Guide to Wireless Interpretation Equipment Rental

Published June 19, 2016


this guide is intended to help meeting professionals plan wireless simultaneous interpretation for single-room, one-to-many meetings. The guide assumes a basic understanding of meeting planning and conference setups.

Who This Guide Is For

This guide is for meeting professionals involved in planning multi-language events featuring simultaneous interpretation: meeting, convention and event planners, producers, technical directors, business development and sales people, account managers, project managers, and production managers.

If conferences, conventions and meetings are a vehicle to educate, communicate and delight, why are there still events where the quality of the simultaneous interpretation is not to everyone's satisfaction?

when we treat the interpretation as an afterthought, we limit our ability to provide attendees who need language interpretation with the audience experience they deserve. With the US multicultural population growing and the United States remaining a premier conference destination, events with more than one language will remain a constant. Knowledge of what simultaneous interpretation entails and best practices for its staging can help meeting professionals push simultaneous interpretation to the heart of the event and attendee experience.

In this guide, we share our experience and practical tips to help you plan for a successful simultaneous interpretation experience at a typical .

We'll provide insights on wireless interpretation equipment, sound reinforcement, room layout, and working with interpreters. We hope it will inspire you and your team to start thinking interpretation-first for better results.

picture of set up for one-to-many meeting with interpreter booth

think "interpretation-first"

thinking about the event's interpretation needs during each stage of the planning process will help make better event design decisions, which, in turn, will result into better meetings.

wireless interpretation equipment basics

"Interpretation equipment" or "language distribution" refers to a system that allows interpreters to transmit the simultaneous interpretation and the audience to listen via the use of earphones or headphones. Colloquially, it's frequently referred to as "translation equipment" or "a simultaneous translation system."

wireless simultaneous interpretation equipment, designed for one-way communication makes it simple to distribute languages to an audience for meeting styles such as:

wireless simultaneous interpretation (SI) equipment allows for fast setup and breakdown, making it ideal for short-term events taking place at venues without a permanent language distribution system installation.

Overview of Wireless SI Technologies

Two technologies are in use for wireless simultaneous interpretation (SI):

RF interpretation equipment

wireless interpretation equipment built on radio frequency (RF) technology is widely in use all over the world. Permissible license free frequencies vary per geographic region based on local laws and regulations. RF systems can be analog or digital.

analog RF systems

in the United States, the most robust RF systems for one way wireless simultaneous interpretation (SI) are analog FM systems in the VHF band. The 72 Mhz-76 Mhz and the 216 Mhz bands are reserved by the FCC for auditory assistance communications, including simultaneous language translation. Small and large events have successfully been using analog FM systems for decades as they present many advantages. One of the advantages of the 72-76 Mhz frequency range and 216 Mhz band is the higher chance for an unlicensed user to find an available channel.

we generally prefer the 72 Mhz band for simultaneous interpretation for various reasons. Firstly it can fit more channels than any other permissible frequency in the US. Depending on the transmitter manufacturer, up to six to eight channels can be used simultaneously in the 72 Mhz band. Secondly, the lower the frequency the less power you need to transmit over the same distance. As a result with 72 Mhz your equipment benefits from a long battery life. Thirdly, in an optimal RF environment, channels using the 72 Mhz band with a stationary transmitter can reach a distance of 1000-1500 ft. A portable body pack style transmitter will have a typical range of 100ft-150 ft.

while other users in the 72 Mhz band may be encountered, the ones with high power transmitters will occupy a limited number of frequencies. These high-power users are mandated to be registered in FCC dababases and the frequencies they occupy in your area of interest can be verified ahead of time. A venue can facilitate the liasing between users within its facility to coordinate the use of the frequencies to accomodate everyone.

The 216 Mhz band can typically be a perfectly respectable alternative if you do not need more than three channels to work simultaneously on wide band or five channels simultaneously on narrow band.

the below is an example of a typical RF conference interpretation for a one-to-many meeting. Most scenarios for one-to-many and can be accomodated in our rentals of interpretation equipment.

A typical RF conference interpretation setup
  1. the speaker of the talks into a microphone (called the floor mic, the floor audio, the floor feed or the audio feed). For optimal results, all speakers should use a microphone to provide the interpreter with a direct audio feed.

  2. the floor audio is fed via the "PA system" to the interpreters, who listen through headphones connected to the interpreter console from an isolated location; usually, an interpreter isolation booth at the back of the room or, sometimes, a completely separate room.

    In a conference interpretation setup, a team of two interpreters is assigned to each language direction. This means that, for example, English into Spanish is handled by the two-person interpreter team in the Spanish and English into French is performed by the two interpreters in the French booth.

  3. the interpreters take turns speaking their interpretation simultaneously into a microphone, alternating shifts every 20-30 minutes. The interpretation is broadcast wirelessly to the audience through receivers equipped with earphones or headphones.

line diagram of conference interpretation set up

digital RF systems

for simultaneous interpretation the only digital RF systems we've seen to date are tour-guide style portable systems in the 2.4 Ghz band.

These digital systems for simultaneous interpretation use frequency hopping technology in the 2.4 Ghz UHF band as a means to avoid RF interference. We see these 2.4 Ghz digital systems as an alternative for environments where our preferred portable analog systems are not usable, where there is a need for two-way communications, or where the size and aesthetics of the device play a major role in the user preference. However for the purposes of this guide we will focus strictly on analog RF systems.

good to know

The fact that a device has a digital display does not automatically mean it is a digital RF device. A device with a digital display can still be sending or receiving an analog RF signal.

configuration of analog RF systems

the convenience, flexibility, portability and fast deployment capability of RF technology makes it a premier choice for events and rentals where interpretation equipment is used temporarily. An analog RF system can be stationary or portable.

A typical analog RF system consists of one transmitter per channel and one receiver per attendee. RF transmitters are available in stationary and portable (body pack) formats.

stationary RF systems

For conference interpretation applications, an interpreter console is typically used along with a stationary transmitter setup. Stationary systems are usually operated by a simultaneous interpretation technician.

The big advantage of professional stationary analog RF systems is that their transmission distance and direction can be manipulated. For mission critical operation, we encourage the presence of an RF engineer or experienced AV technician with a spectrum analyzer, external antennas and filters, especially in rooms with unproven shielding.

portable RF systems

Portable RF systems are easy to use and can be operated by the end user without the need for a dedicated AV technician. Portable analog RF systems are frequently referred to as "portable FM systems".

see how tours and small meetings can benefit from portable interpretation equipment. Learn more.

to learn more about the use of tour guide style, wireless portable RF systems for simultaneous intepretation versus RF conference interpretation systems read The Event Planner's Guide to RF Wireless Simultaneous Interpretation.

infrared (IR) interpretation equipment

Two types of infrared technologies are in use for IR wireless interpretation:

The major reasons to use IR for wireless interpretation are when there is a big potential for RF interference or when the meeting content is confidential and security is required to prevent eavesdropping by outsiders.

infrared is line of sight and the audio thus is confined to the room(s).

Analog IR

We do not recommend use of analog infrared for rentals. We see analog IR as suitable for certain permanent installations in a controlled stable environment.

Digital IR

While more costly, digital infrared is more robust and flexible for deployment throughout permanent and temporary installations. Rent digital infrared interpretation equipment for guaranteed performance in uncontrolled environments.

a typical digital infrared conference interpretation setup consists of:

(coming soon: flow chart of digital IR)

Digital IR language distribution systems are stationary and usually operated by professional simultaneous interpretation technicians.

is RF or IR best for my event ?

for some environments and meeting requirements, opting for a language interpretation system that operates with an infrared wireless transmitter and infrared wireless receivers is a must. At other times, choosing an interpretation system based on radio frequency (RF) technology may be the preferred option.

RF systems

if you're planning an event where the interpreter has to move from one location to the next, RF technology may be the way to go. RF portable transmitters are a favorite for events where mobility is required.

digital RF systems can provide somewhat better audio quality than analog FM systems, yet are less flexible. Just because an RF interpretation system is digital, it does not necessarily mean it's the better choice for your event. Every RF environment is unique and having a constant and interference-free connection is not always a guarantee.

IR systems

digital Infrared (IR) technology is a viable option for a number of use cases, for example:

Plan ahead

it is recommended to start planning for the equipment early on and obtain as much information as possible about the event requirements and the environment where the interpretation equipment will be operated. Share this information with your interpretation equipment rental company and consult with them on the best solution for your specific needs. When possible, plan for a rehearsal day. Testing the equipment onsite with ample time prior to the event start is always a good idea.

if your application is mission-critical, proper care must be taken to ensure redundancy in the system design - whether it be having the safety blanket of digital IR or additional RF channels ready to be activated at a moment's notice. Involve the interpretation equipment provider early on so that sufficient time is available for the system to be designed based on your specific environment.

Prepare for the rental

the following questions are a good start to scope out the wireless interpretation equipment rental.

  • How many rooms need the interpretation?

    > Is the meeting in a single room or are there concurrent meetings with need for interpretation in simultaneous mode? Will the group be split up or will any sessions be held in breakout rooms?

  • Has an optimal event space been selected?

    > Noise levels and poor room acoustics can significantly impair the interpreters trying to do their job. The type of flooring of the event room can affect sound quality. We understand this is often a variable outside of your control. Just keep in mind that carpet is best for acoustics!

  • Is the event content classified as confidential thereby requiring security against eavesdropping?

    > If you need to make sure nobody outside of the event can intercept the content of your presentations, you should consider digital infrared technology, which is more secure than radio frequency based equipment.

  • Does the equipment need to be portable such as for a tour or traveling group?

    > Portable systems use RF technology. Portable analog FM systems are simple to operate without the need for a simultaneous interpretation (SI) technician.

  • If I rent a portable FM system, am I prepared to operate it on my own?

    > If you rent a simple to use portable FM system, you'll save on equipment cost and labor but take on responsibility for the technical planning, onsite operation, management and any troubleshooting of the interpretation equipment.

  • Do I want an interpreter booth? If so, should it be a tabletop booth or a full size one?

    >Consider that any noise that is not the presenters' voice can be a distraction for the interpreters and should be minimized. A full size interpreter booth rental goes a long way towards providing a comfortable space for the interpreters to work and the needed sound isolation. A tabletop booth rental with partial sound isolation can also work well for many scenarios. Keep in mind the footprint of the booth and the available space in the room. The interpreter's station should have proper comfortable seating, room temperature and a reading lamp for each interpreter.

  • What challenges can be anticipated using interpretation equipment at my chosen event venue?

    > Potential issues with RF equipment at the location include:

    • anyone close by using the same RF transmission frequency, with an equal or more powerful system;
    • a nearby TV antenna signal that can cause interference;
    • any physical elements (like pillars and walls) between the transmitter and the receivers, which might block the transmission. This includes metal walls, thick brick, concrete or masonry walls that exist in the deployment space
    • If you're considering using a portable 2.4 Ghz digital interpretation system with many people in a small area, the closer the receiver is held to the body, the more likely there will be body shielding. There is no calculator to predict body shielding. It's a trial and error test. Every person uses the system in a different manner
  • Is a standard audio quality acceptable or does the event require high fidelity audio?

    >The audio quality of analog RF (FM) interpretation systems from leading brands is more or less comparable. For a slightly better audio experience at a tour, you could consider a digital portable 2.4 Ghz system or, for hi-fidelity audio at a conference upgrade to a digital infrared system.

  • What will be the language directions and the number of interpreters per booth?

    > In a UN-style format, interpreters only interpret into their respective mother tongue (called “A” language). Alternatively, if you are operating with a tight budget, you can have interpreters work "dual language direction" by having them also interpret into their other language in which they are fluent but not native (“B” language).

    >The number of interpreters will affect the amount of interpretation equipment required. For example: If you are having interpreters only interpret into their "A" language, in most cases you'll need twice the number of interpreters, channels and booths.

  • How many channels will be needed for the simultaneous interpretation?

    > Calculate one channel per language direction.

    Example A: English into Spanish is 1-channel.
    Example B: English into Spanish and Spanish into English are 2-channels.

  • How will the interpreter(s) hear?

    >For the interpreters to hear clearly what is being said, audio of the presenter(s) is to be transmitted directly to the interpreter's station. Find out if there will be a dedicated audio feed from the AV provider so that a direct line can be run from the conference room’s PA system to the interpretation equipment. To perform their job at the best of their ability, the interpreters need to hear the speakers/presenters well at all times during the event. There are four ways to accomplish this.

    1. recommended: dedicated audio feed from mixing board

    the presenters or panelists are given individual microphones as part of the venue's sound reinforcement setup and the simultaneous interpretation system provider receives an audio feed from the venue's mixing board.

    Best practice calls for interpreters to use headphones, a microphone and an interpreter console from where they can control the sound level during the event and make adjustments as needed. If there is sound reinforcement at the event and the interpretation equipment comes with an interpreter console (portable FM systems do not), the interpreter’s headphones should connect via the interpreter console to the sound system’s mixing board “audio out” (usually via a 3-pin male XLR floor out), which feeds the audio directly from the speakers.

    the interpretation equipment provider should coordinate with the sound reinforcement provider and do a sound check prior to the start of the event.

    2. alternative: headphones from mixing board

    using a sound system (either the one provided by the event venue – if available – or a rental), the interpreter’s headphones are connected directly to the system’s mixing board “audio out”, which feeds the audio directly from the speakers. If the venue has an AV technician working your event, they will likely be able to do this for you. If not, you will have to set this up yourself.

    (coming soon: visual of mixing board with audio out)

    this is the best solution to give the interpreters quality audio when using a simultaneous interpretation system without interpreter console (like a portable FM system). You just have to make sure the interpreter’s headphones have a long enough wire to reach from the mixing board to the interpreter booth (or wherever the interpreters are going to be, if you are not using a booth). Take this into consideration while drawing your room diagram.

    the downside of this approach is that, without the console, the interpreter does not have a way to control the incoming audio levels and instead relies on the technician operating the mixing board to provide an optimal sound volume. This is why it is important to test the system before the event and make sure the audio level is optimal for the interpreters.

    3. workaround: ad-hoc wireless feed

    if there is no sound reinforcement, you can rent an additional portable beltpack transmitter and an extra receiver. The presenter will use the transmitter on a separate channel from the one selected for the transmitter used by the interpreter. The interpreter will then tune the extra receiver to the presenter's transmitter’s channel to get a direct wireless audio feed.

    for your room setup, you will have to take into account that the transmission range of a portable beltpack transmitter is approx 100 feet, so the interpreter cannot be set up farther than 100 feet from the presenter's transmitter.

    in addition, since you will be working with multiple transmitters, you must make sure to leave at least two free channels between each transmitter’s frequency to avoid interference.

    this solution can be acceptable for small-scale one-person presentations or if multiple presenters will await their turn to speak using the same microphone.

    for scenarios with multiple presenters or panelists using table mics, in a many to many meeting, it is advisable to use discussion units or a wireless conference system that routes the microphones to a system control unit such as Bosch. To buy or rent a conference system, please visit our section AV Rental & Sales.

    4. no audio feed

    At times, for budgetary or technical reasons, there is no possibility to get an audio feed to the interpreter. As a last resort, you could have the interpreter simply listen naturally to the speaker - with no headphones and no audio feed.

    in this scenario, the quality of the audio heard by the interpreter will be inferior as it is affected by room noise such as: audience members talking among themselves, the sound of people eating during a luncheon or dinner, waiting staff serving or clearing tables.

    any extraneous noise might impair the interpreters' ability to concentrate. Some interpreters may be reluctant to accept to work without a proper audio feed. To avoid surprises, it is best to discuss the absence of an audio feed with the interpreter team or interpretation company at booking time.

  • How will the interpreter(s) see?

    >Are the interpreters in the same room as the presenters or panelists with a clear view of the presentation and screens? If the interpreters are going to be located in another space, you should budget for a camera package with video monitors and associated cabling so the interpreters can get a real time video feed of the speakers.

  • Does my event require relay interpreting?

    > Relay interpretation involves one interpreter taking the output of another interpreter as the source and rendering the message in a language understood by all the other interpreters. This "indirect interpretation" is then rendered to the target language audience. This technique is used when there are multiple target languages in an event and no single interpreter works in all of the languages, or when no interpreter can be located for a certain language combination.

  • Is there a Q&A session that requires interpretation? If so, do I want it to be carried out in consecutive or simultaneous mode?

    > The interpretation of the Q&A can be performed in consecutive mode where one of the interpreters steps out of the booth, gets mic’d separately and is seated next to the panelist so he/she can take any necessary notes. Alternatively the Q&A session can be interpreted in simultaneous mode using the interpretation system.

    planning the interpretation of the Q&A session

    if you are planning to have a question and answer session, you have two options.

    Q&A setup without using the interpretation system

    the Q&A session is done in consecutive interpretation mode, which will require the interpreter to go sit next to the presenters without the need to use the simultaneous interpretation system. The interpreter will hear the question from the audience, interpret it to the presenter, then listen to the presenter's answer and interpret it back to the audience.

    A Q&A session using consecutive interpretation with two language combinations takes about twice the time as compared to simultaneous interpretati

    Q&A setup using the interpretation system

    if you want to do simultaneous interpretation during the Q&A session, you will need a roving Q&A microphone to pass around to the members of the audience who want to ask questions or the people asking questions can walk up to a centrally placed Q&A microphone on a stand.

    the interpreter gets a direct audio feed from the roving microphone (in addition to the audio feed from the presenter's microphone). The presenters get their own wireless FM receivers [does this apply to every case? if not, how should we edit?] to listen to the interpretation, then give their answers speaking into their microphone. Just like during the presentation, the interpretation of the answer is transmitted to the attendees through their receivers.


    let’s assume your event includes presenters speaking in English to a Spanish-speaking audience. During the presentation, the interpreters will interpret English into Spanish on, say, channel 1.

    after the presentation, you have a Q&A session where the audience asks questions to the presenters. If you are providing simultaneous interpretation for the Qamp;A session, you are now dealing with a second language direction, as the interpreters have to interpret the questions from Spanish into English for the presenters.

    the more audience-friendly solution is to have a separate channel (say, channel 3) for the Spanish into English interpretation. This way, the presenters will only hear the Spanish into English interpretation of the questions and the Spanish audience will only hear the English into Spanish interpretation of the answers because you have a dedicated channel for each language direction.

    however, if you want to rent only one transmitter, you will have to use channel 1 for both the Spanish into English interpretation of the questions and the English into Spanish interpretation of the answers. This means the audience and the presenters will hear both directions of interpretation, even the one they don’t really need. Their only other option is to take off the receiver’s headsets during the interpretation of their own language.

    while we recommend having one channel per language direction, the best solution for you will depend on your budget and the type of experience you want your attendees to have.

steps after booking the rental

connect the stakeholders

minimize the risk of misunderstandings and costly last-minute changes by getting the various service providers to speak early on and keep each other in the loop.

supply details to your provider

make sure your interpretation equipment vendor has all the event details including:

taking the time to prepare a visual of the room layout is helpful to all stakeholders. Read our 10 golden rules to lay out a room for wireless simultaneous interpretation.

request a quote or ask a question

call us at 212-489-6035 to speak with a interpretation equipment specialist.

learn more about our interpretation equipment rentals.


*NOTICE: these guide and articles are intended to serve as a resource on the topic of interpretation services and interpretation equipment rental and reduce the possibility of issues occurring at time of event due to improper operation of interpretation equipment by customer or insufficient planning during the event preparation phase. It is not intended as professional advice, nor is it a complete compendium of the information available in this area. We make no warranties, express or implied, regarding this information. If you have questions or need specific advice for your situation, refer to your contract email info@iprobesolutions.com or contact iProbe at 1-212-489-6035. Refer to the current iProbe Service Guide for terms, conditions, and limitations applicable to iProbe services.