Rulings of al-Madd
    in Qur’aan recitation
Question

                Would please tell me what the symbol
    "~" has effect on the meaning of word or phrase of the holy QuranIf some one does not Prolong the sound of the letter under "~"
    would that change the meanings ?
Praise be to Allah.This symbol "~" is used to indicate places where a Madd
    (elongation) that is longer than the regular elongation is required. It is used in places
    where the Madd is compulsory (Madd laazim), as in the word "At-Taammah ", where
    the elongation is six harakaat or counts. One harakah is equal to the time taken to curl
    or stretch one finger. This symbol is also used for al-Madd al-Muttasal (where a long
    vowel is followed by a hamzah in one word), such as "sawaa'un 'alaynaa ", where
    the Madd is between four and six harakaat. And it is used for al-Madd al-Munfassal, (where
    one word ends with a long vowel and is immediately followed by a word that starts with a
    hamzah), as in the phrase "fee aadhaaninaa waqar ", where the Madd is four or
    five harakaat.
    This symbol does not have any effect on the meanings of the words; it is only used to
    indicate some kinds of Madds or elongations, as explained above. The Madd which is longer
    than the regular elongation (two harakaat) does not change the meaning when you do it. But
    we have to follow the Sunnah of recitation, and the Prophet 
 (peace and blessings of
    Allaah be upon him) used to elongate some vowels in his recitation. And Allaah knows best.