It very well could be a hearing imparement!! It may not be a permanent imparement - i.e., it could just be fluid that has remained in the ear for a long time, but hasn't caused infection. I would take her to an ENT that has a full audiology lab (meaning a pure sound proof testing room). Dr. Wade Cressman is GREAT!! I have a hearing impared child (high frequency hearing loss in his right ear only), but it has not affected his talking. I also have a child that has speech delay with non-permanent hearing issues (like the fluid that I mentioned earlier).
In addition, the state of Florida offers a program called Fiddlers. They will asses your daughter and her abilities to see if there is an issue. However, the will not do this until you have had her hearing checked out. If there is a delay in her speech, they will provide you (free of charge) a therapist that will assist her in speech. If you daughter goes to a daycare, the therapist will go to the daycare and do therapy during the day and communicate with you as to her progress and things to do at home. The number to call is ###-###-####.
My recommendation is to schedule a visit with the ENT for an over view and hearing test and call to get on the schedule for the Fiddlers program. Unfortunately, it can take a few months to get things rolling with that program - obviosly because it is state funded.
One more note - just because this is state funded, don't think that you aren't getting the best therapists. These are therapists that have their own practices and have also been contracted with the state to run the program. They are all educated and experienced - not students.
Good luck and don't let this stand by! Trying to correct speech is more difficult the older they get. And if there is a hearing problem, it will affect her learning ability and safety!
Sam