Wow. I've never actually used a live spectrogram, and it's really educational.
Use the mic input option and try saying different vowels, or different held consonants like "mmmm" vs "nnnn". It's really interesting to see how the patterns of overtones change, which is what makes the sounds unique.
there are several spectrogram apps for your phone. It is really fun to have them "on" all the time and see what can be heard around. My favourite patterns are those of an old, rusty door, scratching the floor as it opens.
Use the mic input option and try saying different vowels, or different held consonants like "mmmm" vs "nnnn". It's really interesting to see how the patterns of overtones change, which is what makes the sounds unique.