def check_for_wav_only(list_values):
    """
    Get the list of wav files .wav and .WAV format only
    """
    wav_files = []
    for each_value in list_values:
        if each_value[-3:] == "WAV"  or each_value[-3:] == "wav":
            wav_files.append(each_value)
    return wav_files