Yes, you can use portable transmitters indoors and they will fulfill the same function as the desktop version. However, we strongly recommend that if you don’t need to use the transmitter outdoors where there may not be an electrical outlet available, you use a system with the desktop-based one. This is because it has several advantages and features that the portable version lacks, including more than three times the range and the possibility of the interpreter listening to the speaker’s voice though headphones thanks to the unique interpreting monitoring function of the T-500 stationary transmitter.