def METHOD_NAME(self, audio, rate):
    """
    Read audio to raw waveforms and sample rates.
    Args:
        audio: audio|list
        rate: optional sample rate
    Returns:
        List of (audio data, sample rate)
    """
    speech = []
    for x in audio:
        if isinstance(x, str):
            # Read file
            raw, samplerate = sf.METHOD_NAME(x)
        elif isinstance(x, tuple):
            # Input is NumPy array and sample rate
            raw, samplerate = x
        else:
            # Input is NumPy array
            raw, samplerate = x, rate
        speech.append((raw, samplerate))
    return speech