Ruling on reciting the Talbiyah in unison

Praise be to Allah.

That is not permissible because it is not narrated that the Prophet (peace and blessings of Allaah be upon him) or any of the Rightly Guided Caliphs (may Allaah be pleased with them) who succeeded him did that; rather it is a bid’ah (innovation). 

And Allaah is the Source of strength. May Allaah send blessings and peace upon our Prophet Muhammad and his family and companions. End quote. 

Standing Committee for Academic Research and Issuing Fatwas 

Shaykh ‘Abd al-‘Azeez ibn ‘Abd-Allaah ibn Baaz, Shaykh ‘Abd al-Razzaaq ‘Afeefi, Shaykh ‘Abd-Allaah ibn Qa’ood. 

Fataawa al-Lajnah al-Daa’imah li’l-Buhooth al-‘Ilmiyyah wa’l-Ifta (11/358) 

See also the answer to question no. 33746.