A) Your conference is bi-lingual - in other words it goes back and forth between 2 languages. For example, English to Spanish AND Spanish to English.
B) Your event goes from one language into several others. For example from English into Spanish, and from English into Chinese.
Multi-language systems can be quite complicated to choose. It would probably be a good idea to contact us to make sure you order the right components for your particular needs.
If situation A applies to you, the Williams Sound systems will handle the situation very well, and systems like the TGS Pro Multi and TGS Pro 738 contain everything you need (if you add headphones or earpieces).
If situation B applies, it's a little more complicated. Any of the Williams or Listen Tech systems will work for you, but you will need to add an extra transmitter and microphone for each language above 1. For example, if you are interpreting from English to Spanish and from English to Chinese, you will need to add a second transmitter, as the systems only include 1. Feel free to call us if you are confused - there's a lot to know!