Some readers read the Quran out loud and it may be because the phone picks up the sound. In mosques, you will find some worshipers and reciters who may be distracted by the loud sound. Ibn Baz (may Allah have mercy on him) said: It is okay for a person to read aloud, but it does not harm anyone in public. However, if there are worshipers around him or around him, he reads a reading that does not harm them, does not wear their prayers and read them. He lowers his voice so as not to harm them. If there are people around him who listen to him and benefit from his reading, it is okay to raise his voice in order to hear them and benefit if it does not harm any of the readers around him or the worshippers around him. I hope there will be a message warning readers not to raise their voice and may God reward you well.