Abstract: An audio-controlling system has a mixer and an audio playing and controlling device. The mixer mixes an external audio signal and a controlling signal and then outputs a mixed audio signal to the audio playing and controlling device. The audio playing and controlling device is connected to the mixer to receive the mixed audio signal, plays the mixed audio signal and executes action according to controlling signal of the mixed audio signal. Therefore, The audio playing unit plays audio signal and the decoding unit outputs command codes to the actuator in wire or wireless way, so that the actuator automatically operates at the same time.

Abstract: An FM signal transmitter has a processing module, a connecting module and an FM transmitting module. The connecting module is electronically connected to the processing module and has a Universal Serial Bus (USB) unit that is selectively connected to a computer and receives audio data from the computer, wherein the USB unit has a memory storing a preset USB class. The FM transmitting module is electronically connected to and controlled by the processing module to broadcast an FM signal corresponding to the audio data under a specific frequency. The computer may perform an audio filtering method to successively rewrite the preset USB class from USB-HID, USB-AUDIO and USB-HID so that the computer can transmit audio data excluding system generated sounds to the FM signal transmitter.