I have been looking all over the internet for an answer to my problem. It happened to my sister a while ago however hasn't been effecting me till recently. What happens is not when I plug in any pair of headphones to listen to audio, the computer doesn't shut off external speakers. I have seen some people get some really good help here so I was hoping someone could finally fix the issue.
It may be a matter of configurations. Did it just start happening? If so, what changes have been made? Maybe you started using a new app? What has changed? Also, let us know what OS you are using, along with details that important...nothing but computer specific details!!