# Audio ## How should we set Audio? AAC for live broadcasting, G.711U for video surveillance. ## Why does it not work to stream to YouTube when switching audio input from HDMI to Line-in? It's necessary to reboot the device directly after that to make it valid because the encoding algorithm is switched accordingly which causes the audio will be pending. ## Why are there so much noises with Aux Audio? It’s strongly recommended to use standard 3.5mm audio connector with two black circles on it like below photo and volume should be less than 80. ![3.5mm Audio Connector](/files/-MQ-t4qB_khkQPGnAVz1) ## Can we use external audio by 3.5mm and audio by HDMI? Negative, either of them can be used. ## Can we change the input volume and sampling rate of line-in audio? Yes, it's only supported in the new firmwares. ## How should we clear voice of current of encoder? Please follow below steps: * Get the audio source by playing music on your smartphone, it's just used for verifying there is no voice of current of encoder; * Buy one audio filter * Get encoder and audio filter connected with GND. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.exvist.com/encoder-pro/resources/faq/video-audio/audio.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.