If a person utters Talaaq and repeats to himself voice is not heard by himself does Talaaq take place?

In the Name of Allah, the Most Gracious, the Most Merciful.

As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.

To merely think about Talaaq does not constitute Talaaq.[1] In your case if you had thought these words in your mind but did not mention them on your tongue, Talaaq will not take place.

And Allah Ta’āla Knows Best
Mawlana Ali bin Cassim
Student Darul Iftaa
Los Angeles, CA (USA)

Checked and Approved by,
Mufti Ebrahim Desai.
www.daruliftaa.net