While a faint swishing sound is normal when you are draining water out of a sink or tub, you may be startled to hear a gurgle. A gurgling sound may be indicative of problems that require a plumber's assistance.
A gurgling in the drain results from air trapped in the pipes somewhere along the line. There may also be an issue with a blockage somewhere along the drain. Because if this, you may also notice that the water is slow to drain.
In many cases, installing a vent in the pipe fixes the problem. A vent in the pipe allows air to escape while still keeping in the water. A drain vent can be installed by the homeowner, but if you are uncomfortable tinkering with your pipes, contact a professional plumber.
Garbage Disposal Issues
In some cases, the gurgling is caused by a clog in the garbage disposal. If there is debris or sediment in the garbage disposal, there may also be air trapped in it. Turn off the power and reset the machine or use an Allen wrench to move the motor back and forth, clearing the clog.