Receivers
Usually only one channel is used because only one foreign language needs to be interpreted to some members of the audience. However, in some instances a second or even third language might need to be interpreted, and in those cases having more than one channel becomes useful. Audience members can tune their FM receiver into the corresponding channel to listen to their language. Multichannel receivers are also recommended when there is simultaneous interpretation in multiple adjacent rooms or when there is not only simultaneous interpretation in one room but also assistive listening for the hearing impaired. Keep in mind that you’ll need 1 multichannel transmitter per auditory source, each only tuned into a different channel or frequency.
The two main reasons are that built-in lithium batteries always present some degree of fire hazard, and while that can be dangerous, it can also limit some of the spaces where such devices can be used and transported, for example some airline might forbit them on board. The other reason is that all batteries degrade over time, but if you can easily replace them like with AAAs that won’t be a problem, but if they are built-in after a few years you’ll be stuck with a battery in constant need of recharge.
The silver ones are the Enersound R-120 and are multichannel and in most cases include lifetime warranty; at the press of a button the end user can switch among different channels with different frequencies already assigned to each one. The black or dark grey ones are the Enersound R-100, and they feature a single programmable channel, which can be set to different frequencies but not by the end user. The R-100 includes 3-year warranty.
You can connect an unlimited number of receivers to a single transmitter, if they are within the transmitter’s range, which may be 150 to 1000 ft depending on the type of transmitter and antenna used.
A transceiver is a wireless communication device that combines a transmitter and a receiver in a single unit. This means that the person using it can both speak to transmit a message and listen to another speaker, unlike receivers that are used to listen only.