Methods and apparatus for identifying a digital audio signal are described. An example apparatus for identifying a digital audio signal includes an input to receive the digital audio signal, which includes data from a broadcast or a stored digital program signal. The example apparatus also includes a detector to receive the digital audio signal from the input and determine whether the received digital audio signal is uncompressed as received at the input; a decoder to receive the digital audio signal from the detector when the digital audio signal is compressed as received at the input and identify any first program-identifying code in an auxiliary field of the compressed digital audio signal; and a code reader to receive the digital audio signal from the detector when the digital audio signal is uncompressed as received at the input and receive the digital audio signal from a decompressor when the digital audio signal is compressed as received at the input. Additionally, the code reader is to identify any second program-identifying code in a decompressed or uncompressed portion of the digital audio signal when the first program-identifying code is not identified in the auxiliary field or when the digital audio signal is uncompressed as received at the input.