A sound signal detection device is closed. The sound signal detection device is connected between an audio output device and a speaker apparatus. The sound signal detection device includes a first connecting port, a second connecting port, a microphone, and a processing module. The first connecting port connects to the audio output device and acquires a first sound signal. The second connecting port is used for outputting the first sound signal to the speaker apparatus. The microphone is used for receiving a second sound signal from the speaker apparatus. The process module is electrically connected to the microphone and used for detecting a volume of the second sound signal to generate a real volume signal.