Shure E2 Isolation Earphones

These little earbuds are designed as IEMs, In Ear Monitors, for stage musicians and the like. Hence, they have incredible sound isolation. I would feel comfortable using them as hearing protection while mowing the lawn. I would estimate that would a good fit, the Noise Reduction Rating would be about 20dB.
 
Since the drivers are fairly small (~1cm), they have just the amount of bass one would expect: little. It's there, but weak. Of course, if you buy these, you should expect that. If you use them in a portable situation, any bass produced by headphones would likely be overpowered by outside sound. On a stage, the subwoofers would fill in what you needed. I recommend them for both of those situations.