TRACON Controller reported reporting to work and learning of new procedures that were not briefed resulting in confusion in the TRACON and Tower.

Narrative

This report is a direct result of another report:BNA has updated our noise abatement headings. When I arrived to work today; the new headings were effective immediately. I; along with others; had not received the facility briefing on the new headings and so I was instructed to utilize the old headings until I could be briefed. This also happened to other controllers. This led to a lot confusion for the first half of my shift because controllers were using headings based on whether or not they had been briefed on the new headings. My first round in the TRACON; I simply asked the local controller to scan down the departures with the assigned printed on the strip so that I was clear as to what heading the aircraft would be on. This is not required per the new noise abatement SOP; however; I thought it would be helpful. This then led to confusion in the tower. The OS (Operations Supervisor) in the TRACON then instructed the tower to scan down all departures with the assigned heading to alleviate any confusion. The acting ATM (Air Traffic Manager) and acting OM; I believe; were both in the tower communicating with the OS in the TRACON. There was a lot of background noise in the TRACON in regards to all of this confusion. While I was working radar; our procedure for handling the new headings changed four different times in my one session.First; when I got in the TRACON my assumption was that we were on old noise abatement procedures.Second; I was advised we were on new noise abatement procedures and headings will not be scanned down. Third; I was told that local could use old noise headings and not put the heading on the strip indicating the use of an old heading; If local was going to use new noise abatement headings they will scan the heading on the strip. Fourth; I was told that we would just go off of noise abatement procedures and that all headings will be scanned on the strip. There was also a lot of discussion/confusion as to when the departure controller has control for departures. This was also discussed and changed several times which caused a distraction. 'During this distracting time; Aircraft X departed BNA on a 250 heading which is a new noise heading. Normally; the same aircraft would have departed on a 275 heading. At this time; I had not received the new headings briefing. Because of confusion as to when I had control; on initial contact; I radar identified the aircraft and climbed them to 6000' because of traffic at 7000' and left them on tower assigned heading. I waited for the conflict to resolve itself and climbed the aircraft to 15;000' per our LOA with ZME. At the time the conflict resolved itself; the aircraft was approximately 15 SW of BNA. Due to the new headings that I had not been briefed on; the aircraft was pointed out of the appropriate gate and gave the appearance that it was tracking the right direction. This led to me forgetting to put the aircraft on course; I simply left them on tower assigned heading out the gate; which is a violation of the LOA with ZME. This just coincidentally looked as though the aircraft was on course. I would recommend that if a procedure is going to be changed; the entire workforce is fully aware before the changed is implemented. I know for a fact that if I had an appropriate briefing knew exactly what the new procedure was; that I would not have left the aircraft on the tower assigned heading and instead; put them on course.