The 3M X3A + brown noise will drown out bird chirping and ~95% of human voice noise. The X3A is far more comfortable - slimmer - than the X5A. If you need max reduction of neighbor annoyance, nothing beats the X5A though. Neither of these are particularly expensive, they're both worth trying.

Some people try to use headphone type noise cancellation, which is mediocre at cancelling most noise. I found instead of using headphone noise cancellation, it was far better in most circumstances to use the X3A + earbuds while working - that tandem was very comfortable to wear for long periods of time. The X5A is not very comfortable, it's just max effective.