What to say upon hearing the Athan (call to prayer)

وَأَنَا أَشْهَدُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَحْدَهُ لاَ شَرِيكَ لَهُ وَأَنَّ مُحَمَّداً عَبْدُهُ وَرَسُولُهُ، رَضِيتُ بِاللَّهِ رَبَّاً، وَبِمُحَمَّدٍ رَسُولاً، وَبِالْإِسْلاَمِ دِينَاً

Wa anā ashhadu an lā ilāha illā llāhu waḥdahu lā sharīka lahu waʾanna muḥammadan ʿabduhu wa rasūluhu, raḍītu bi-llāhi rabbā, wa bi-muḥammadin rasūlan, wa bi-l-ʾislāmi dīnā

‘And I too bear witness that none has the right to be worshipped except Allah, alone, without partner, and that Muhammad is His salve and Messenger. I am pleased with Allah as a Lord, and Muhammad as a Messenger and Islam as a religion.’