The microphone and the generator

The BM370 oscilloscope displays the signal coming from the microphone. You can pronounce various letters, such as A, E, I, O, U, and see their waveform. You can hear your own voice when pressing the lower button on the black box. By pushing the upper button, the output of the generator is connected to the loudspeakers. Frequencies from 0,02 to 20 kHz produce audible sound. Very low frequencies are not transmitted efficiently by the loudspeakers. On the other end of the audible spectrum, only children can hear frequencies up to 20 kHz. The frequency response of human ear worsens with age to 10 kHz or even much less.