Hi Farid
I think the Märklin 83307 Delta is a T18 steamer.
Your loco has probably a DCM (Drum Collector Motor) which may need to be replaced with an HDLA motor a 60941 in this case.
I installed such a HDLA on my T18 KPEV but I had to grind a little bit the magnetic core of the motor. This is easy with a mobile drill and a diamond or Corindon disk
This is because most sound decoders work with DC or sinus motors.
Then the sound decoder:
- probably the best choice is a Märklin Sound decoder 60985 It is already programmed with steam sounds and compact packaging
- a alternative is an ESU lok Sound that you may order at some shops (MSL for instance) with a programmed sound for free (Just make your choice among the ESU sound projects

ESU decoders are very fine but a real nightmare to implement / modify with a Märklin CS3 or CS2. Pratically you MUST buy an ESU LokProgrammer.
In my case I prefer spending my money on a CS3 which allows me to drive trains, programm them, interface with my PC for train control (Rocrail)
Märklin offers for free a sound tool and library to program sounds

Here is my T18 KPEV with an HDLA motor and an mSD2 (or mSD3) decoder. I also added a Telex coupling

If you prefer to reuse the existing motor, then the 60906 is for you BUT no sounds
Cheers
Jean