In the ultrasonic sound velocity measuring device, the transmitter S 1 can be replaced by a speaker, and the receiver can be replaced by a microphone?

Traditional speakers can't excite enough strong ultrasonic signals; There is no standing wave oscillation between the speaker and the microphone. If you only measure the speed of sound, you can use your speaker and microphone instead of standing wave method and phase method, and use pulse method to measure the propagation time of sound pulse. But in this way, only one group of students can do experiments. If many students do it together, we won't fight!