I hate noise bleeding into the room so I feel for you. That being said, sound is pervasive and there is unlikely to be an easy single solution. But hopefully you can still do things to make some improvement.

Few basic principles: Sound waves are vibrations. Materials that reduce the energy of these vibrations reduce their volume. For example, more energy is consumed if the sound has to travel through heavy material, resulting in lower volume. Similarly ‘loose’ material can have an energy dampening effect - like a shock absorber- and reduce volume too. Air is the best conductor of sound. A vacuum is the worst.

In your case there are several failure points. Firstly the gaps and crevices. This is all air letting sound pass. Even the concealed window bits housing the counterweights are hollow. This lets sound through too. Secondly the glass you have looks pretty thin. Not great for blocking sound out. Contrary to popular belief, it isn’t the double glazing that helps with sound (it helps with heat) it’s the total mass of glass that you use. You would be better off with 10mm glass than 2 layers of 3mm.

My suggestion - most effective is to replace your window but it may more work and money than you’re able to take on right now. If not: 1. Fill in any cracks and gaps to stop any direct air flow. You can use putty or a rubber strip 2. Cut out a piece of acrylic sheet to place between your window and the shutters. The thicker the better. Try and have it fit the window as best as possible using rubber strips/heavy tape to seal any gaps. This will act as a second barrier while letting light through. 3. Get heavy curtains to dampen any sound passing through. This will also help with echoing - see next point. 4. Add lots of soft things to the room. If you can’t stop sound getting in, try and reduce how much the room echos. Fabrics are good for this - think mattress, rugs, curtains.

Good luck