وَ اقْصِدْ فِیْ مَشْیِكَ وَ اغْضُضْ مِنْ صَوْتِكَ اِنَّ اَنْكَرَ الْاَصْوَاتِ لَصَوْتُ الْحَمِیْرِ۠(۱۹)(سورۃ لقمان)
Translation
And be moderate in your pace and lower your voice; indeed, the most disagreeable of sounds is the voice of donkeys. (19) (Asan Tarjuma-e-Quran)
Meaning: A person should walk at a medium pace; the speed should neither be so fast that it approaches running, nor so slow that it falls into laziness. Even when a person is going to perform prayer in congregation, the Holy Prophet ﷺ forbade him from running and emphasized walking with dignity and tranquility.
And: Lowering the voice does not mean that a person should speak so softly that the listener faces difficulty, but rather it means that the voice should reach those who are intended to hear with clarity. However, shouting and yelling beyond that is against Islamic etiquette. Even if a person is giving a lesson or delivering a sermon, his voice should only be as loud as necessary for his audience to hear and understand. The elders have forbidden raising the voice more than this under this verse. There is a special need for those gentlemen to reflect upon this command who cause distress to people by using loudspeakers unnecessarily. (Asan Tarjuma-e-Quran)