Hi all, have an NEC Aspire M , have extension hearing one side of other calls through her speaker. Do not hear the outside party just the internal extension. Happening over multiple cards she is ext 308 she has heard extension 307 and 322 on calls through her speaker. Any ideas ?

I would lean toward they activated call monitoring, I don't know the feature code to turn it on or off, you should be able to go into class of service and disable it..