'Abdullah bin 'Abdur-Rahman reported:
Abu Sa'id Al-Khudri (May Allah be pleased with him) said to me: "I see that you like living among your sheep in wilderness. So whenever you are with your sheep or in wilderness and you want to call Adhan, you should raise your voice because whoever hears the Adhan, whether a human or jinn or any other creature, will testify for you on the Day of Resurrection." Abu Sa'id added: "I heard this from the Messenger of Allah (ﷺ)."[Al-Bukhari].
App reference: Book 9, Hadith 45
Arabic/English book reference: Book 9, Hadith 1035