These are the tones of Mandarin Chinese
Identify it by clicking on the button with Pinyin. You can press "Repeat".
The labels below the "Say it" buttons show the IPA transcript.
Use the links with "Praat". Right click, copy shortcut, in the Praat menu select "Open", "Read from file ...", and in the "File name:" box, right click, "Paste", "Open", and press the "View & Edit" button. The figures below show you how the frequency varies with the blue line.