We changed to open concept about 8 months ago. I hate it. As you said there are more interruptions and noise. When I’m in the office I use earbuds and listen to music. It really helps

Setting a rule of not doing anything else other than focusing on one task for a dedicated amount of time helps me understand how dedicating my time religiously to one thing enable me to say “no” or “later” to the distractions easily. Knowing when I will be available for those distractions is a helpful habit to develop.

I have my own office but imagine that putting on noise-cancelling headphones would help with one part. The other part would involve talking to your coworkers so they understand that when you have your headphones on, you are in focus mode and are not to be disturbed unless the building burns. There is a third part; you need to take some breaks to provide opportunity (formal meetings, informal breaks) to let your environment be able to reach you.

I guess sometimes the environment can outsmart you, but you can usually set some limits for environment can interact with yourself, and/or discuss this need with them.

Noise cancelling headphones. Coffee shop ambience with background music. A sign that I change on my desk that notifies my coworker when I’m concentrating and when I can be interrupted. A timer to keep focus.