How to stop gurgle noise in kitchen sink?

[celife]

I've noticed in the last week that my kitchen sink (upstairs) makes a gurgling noise when either my shower (upstairs) or washing machine (downstairs) is on. Any ideas on why this is and how to fix it?

 

[phishfood]

Does the kitchen sink have an air admittance valve on it for a vent?

 

[celife]

The kitchen sink does not have an AAV. Air bubbles seem to be coming up via the drain. I should also add that I've lived here 12 years & this is the first time this has happened.

 

[SHR]

Basic symptoms of a clogged drain pipe. Snake it.

 

[celife]

Thanks, SHR...I will.