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.