d04f9e2c_r__The_Last_Airbender_resource__Aang_s_experience
[Chakra] Sound Chakra [Deals with] Truth [Blocked by] Lies [Location] Throat [Aang's experience] 
When Pathik explained that the fifth chakra was blocked by the lies we tell ourselves, Aang remembered the instance when he concealed his true identity from Sokka and Katara, stating that he did not tell them that he was the Avatar at first, because he never wanted to be. Pathik said that Aang could not lie about his own nature and that he needed to accept his destiny as the Avatar. With a sigh and a vision, Aang accepted this idea and successfully opened the Sound Chakra.
Chakras - Avatar Wiki, the Avatar: The Last Airbender resource
Aang's experience