Sometimes you just need to block everything out—and if an isolation chamber isn't feasible, a good set of noise-cancelling headphones pumping your favourite music might be just the thing.

The most high-tech of these sound machines use active noise-cancelling technology, which samples exterior noise and generates sound waves that literally cancel it out, layered on top of your music. Other models just use ear covers and inserts to isolate the user from the world at large.

But with so many different brands and styles on the market, which one will work for you? Should you opt for an over-the-ear model, or ultraportable earbuds? Is Bose—the pioneer—the best, or do other manufacturers offer better deals? We considered five models—three over the ear, and two buds—four of which offer active noise-cancelling technology. Our research revealed that price isn't always the most accurate quality indicator, and when it comes to comfort and convenience, size matters.