Most people probably don’t think much about how their mouth works. We learned to make noises and form words so long ago that it seems totally natural to contort your tongue into various positions to make every sound in the language (or languages) you speak. A new online voice emulator simulates how those sounds are actually made.

As Motherboard discovered, Neil Thapen, a mathematician in Prague who also makes video games, designed a web app called Pink Trombone that mimics how your mouth, nasal cavity, and throat work to create speech.

You can control volume and pitch with the voicebox control bar at the bottom, and click on various parts of the mouth to change the sounds the mouth makes. Move the circle within the tongue control around and you’ll hear vowels; experiment with clicking around the palate or the lips and you’ll hear some consonants (mostly some version of “guuuuuuuh”). You can constrict the throat or connect the nasal cavity to the oral cavity for a sing-song tone.

Play with it here.

[h/t Motherboard