You are unable to use human speech, making it hard to communicate with any but your own species. As a minor trait you can still understand human speech, but needs some sort of device to be able to communicate effectively.

As a major trait you have no conceptual commonality with normal speech, making you unable to understand or communicate with others. No device is able to accurately translate for you, making you reliant on some form of intelligent interpreter. Characters with this trait might take psychic traits to balance this disadvantage so they might read minds directly.