Is listening to the Imam obligatory in the loudly recited prayers, and does prayer become invalid by not doing so?

Scholars have unanimously agreed on the permissibility of listening attentively to the Imam's recitation, with the exception of Surat Al-Fatihah. They differed on whether listening attentively is obligatory or recommended, and whether prayer becomes invalid by not doing so. The preponderant opinion is that prayer does not become invalid by not listening attentively. Therefore, the congregant should recite Al-Fatihah and then listen attentively to the Imam.