This word is used in sura Muzzammil, verse 4 of the Qur’an:
“ and recite the Qur’an in slow measured rhythmic tones ”
The Arabic word translated as “slow, measured rhythmic tones” is tarteel. It is also the term used to define the rules explaining proper recitation of the Qur’an in the manner that Gabriel(A.S) revealed it to Muhammad(P.B.U.H). While reciting one has to keep in mind the fasl (division) and wasl (joining) of words and sentences. The tafseer of the above mentioned ayah according to Ibn Kathir is “recite the Quran slowly, making the letters clear, for this is an assistance in understanding and pondering the meaning of the Quran.”
These charts have been very successful to teach Tajweed (Makharij), revealed that how you can make a sound of single Arabic alphabet.