Traffic can be one of the most difficult types of noise to remove.  In addition to the general wash of traffic, there can be brake squeals, horns, and car-bys that change pitch over time.  While it’s virtually impossible to remove traffic completely, it can often be reduced to a non-obtrusive level.

Surf noise is unique in that it is much like white noise, but it is constantly changing in amplitude and timbre.  Thus even one sentence might require several different levels of noise reduction since the noise floor is constantly shifting.

Hums can be as simple as a hum resulting from a piece of equipment not being grounded properly, or as complex as a buzz comprised of hundreds of pitches that vary in amplitude over time.  These can be very hard to “chase down” because they don’t stay put for very long.

When wireless mics work well, they’re a godsend; when they don’t, they’re reduced to mere guide tracks for eventual ADR (dialogue re-recording).  Mic scrapes, drop-outs, and interference can many times be repaired.

Birds should be seen and not heard (unless you want to hear them.)

Crickets (and Cicadas) are the liability of shooting at some beautiful locations.  Thankfully, we have the tools to remove them.

Sometimes things besides nature are beyond your control;  That neighbor using a leaf blower, or a model airplane convention.  Using advanced techniques, these noises can be removed as well.