***Note[Please note before purchase] this sound module, when changing audio files by connecting to the computer. The computer must be a Windows system and does not support the Apple Mac system!!! Through the USB cable, you can download more than one voice, and each time you press the key, different sounds will be played. You can use the“ CONFIG.TXT ”File, configure the playback mode you need, and adjust the volume. If it doesn't work stably, be sure to try: 1. The audio file must be MP3 format, please check the audio format. 2. Try a new battery. 3. USB connects the computer, format the U disk, and then copy the new audio file in again. The sound is terrible and it turns off after 10 seconds doesn't play song >>>This is feedback from the buyer. We solve the problem for him：Please fill up the battery and do the test again. Because the battery is not enough, it will produce a sound that does not play smoothly.