Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
abudawud:1089Hannād b. al-Sarī > ʿAbdah > Muḥammad / Ibn Isḥāq > al-Zuhrī > al-Sāʾib

There was no other mu'adhdhin (pronouncer) of the Messenger of Allah ﷺ except Bilal. The narrator then reported the tradition to the same effect.  

أبو داود:١٠٨٩حَدَّثَنَا هَنَّادُ بْنُ السَّرِيِّ حَدَّثَنَا عَبْدَةُ عَنْ مُحَمَّدٍ يَعْنِي ابْنَ إِسْحَاقَ عَنِ الزُّهْرِيِّ عَنِ السَّائِبِ قَالَ

لَمْ يَكُنْ لِرَسُولِ اللَّهِ ﷺ إِلاَّ مُؤَذِّنٌ وَاحِدٌ بِلاَلٌ ثُمَّ ذَكَرَ مَعْنَاهُ