The objective of target sound extraction (TSE) is to extract sound sources of a specified class from mixed signals. Research into TSE has been actively conducted with the aim of applying it to immersive systems and auditory devices. We propose to demonstrate a real-time TSE system, which can isolate the signal from a desired sound class from sound mixtures recorded on the fly. This demonstration is based on the recently proposed causal SoundBeam model, which is trained using knowledge distillation (KD) from a non-causal TSE system. Experiments have demonstrated that SoundBeam with KD exhibits superior extraction accuracy compared to a state-of-the-art (SOTA) TSE, i.e., Waveformer. This paper explains the implementation of the proposed real-time TSE demonstration system. It is noteworthy that this demonstration will show for the first time at Interspeech, the ability to extract sound signals of a selected sound event (SE) class in real-time on a laptop.