When it comes to creating an audio offset in EBS, there are primarily two reasons you would need to do this.
1) You're inputting audio from a source that is introducing a consistent latency. For example, you're streaming audio from a mixer that is using very long cables.
2) Your CPU isn't powerful enough to encode the video and audio at the same time while being in sync.
Here's how you offset the audio in EBS (this function can be performed while streaming. The changes you make are real time).
Click the gear icon associated with the audio source you want to offset and click "Advanced Audio Properties."
In "Advanced Audio Properties", enter a numeric offset number in the "Sync Offset" field.
If the audio is before the video (most common), you will want to use a negative number. Adding a negative number will delay the audio. Start by inputting a smaller number (i.e -500) and see if it helps. If the audio is after the video, you will add a positive number. Start by inputting a smaller number (i.e 500) and see if it helps.