Ibn Umm Maktum was the mu'adhdhin of the Messenger of Allah (May peace be upon him) and he was blind.
أَنَّ ابْنَ أُمِّ مَكْتُومٍ كَانَ مُؤَذِّنًا لِرَسُولِ اللَّهِ ﷺ وَهُوَ أَعْمَى
Ibn Umm Maktum was the mu'adhdhin of the Messenger of Allah (May peace be upon him) and he was blind.
أَنَّ ابْنَ أُمِّ مَكْتُومٍ كَانَ مُؤَذِّنًا لِرَسُولِ اللَّهِ ﷺ وَهُوَ أَعْمَى
The Messenger of Allah ﷺ had two Mu'adhdhins, Bilal and 'Abdullah b. Umm Maktum, who (latter) was blind.
كَانَ لِرَسُولِ اللَّهِ ﷺ مُؤَذِّنَانِ بِلاَلٌ وَابْنُ أُمِّ مَكْتُومٍ الأَعْمَى
Ibn Umm Maktum used to pronounce Adhan at the behest of the Messenger of Allah ﷺ (despite the fact) that he was blind.
كَانَ ابْنُ أُمِّ مَكْتُومٍ يُؤَذِّنُ لِرَسُولِ اللَّهِ ﷺ وَهُوَ أَعْمَى
[Machine] Ibn Umm Maktum was a caller to prayer for the Messenger of Allah ﷺ and he was blind.
أَنَّ ابْنَ أُمِّ مَكْتُومٍ كَانَ مُؤَذِّنًا لِرَسُولِ اللهِ ﷺ وَهُوَ أَعْمَى
"كَانَ للنَّبِىِّ ﷺ مُؤَذِّنَانِ: بِلاَلٌ، وَابْنُ أُمِّ مَكْتُومٍ".
"عن عائشة: أن رسول الله ﷺ كان له مؤذنان: بلال، وابن أم مكتوم".