For use as or in connection with a set-top box, a digital TV broadcast signal is decoded by processing its audio stream into and read from a FIFO buffer. According to certain embodiments, fullness of the FIFO buffer is compared to a reference fullness, which can be updated based on changes to the bit rate of the audio stream. In response to the FIFO buffer fullness, the set top box regulates the rate at which the audio stream is decoded. The disclosed decoding methods do not need to rely on the accuracy or presence of a system time encoded into the broadcast signal.