One recommendation for everyone who suffers in an open office: BrainFM.

Not affiliated with it, but saw it here on HN on a thread about music, tried it out and I love it. I listen to it daily, have probably heard each track at least a hundred times, but it still helps me to focus. With the right headphones (isolating so that volume can be low), I can zoom out and ignore everything around me. Haven't found any other music that can do that, especially when I really have to focus (e.g. reading complicated texts).

Don't know if it really works or if it's just psychological, but I don't care as long as it helps me. Made my life in the office much easier.