Method and apparatus for reducing rate determination errors and their artifacts

A method comprising the steps of:

• receiving a first frame;
• determining a first frame rate for the first frame;
• decoding the first frame according to the first frame rate to produce a speech decoder filter state;
• receiving a second frame;
• determining a second frame rate for the second frame;
• determining, based on the second frame rate, if the first frame rate was in error to produce an error determination;
• updating the speech decoder filter state based on the error determination to produce an updated speech decoder filter state;
• decoding the second frame using the updated speech decoder filter state, wherein the step of determining, based on the second frame rate, if the first frame rate was in error comprises the step of determining if a transition from the first frame rate to the second frame rate was invalid for not conforming to pre-defined, vocoder, rate-transition rules.