Is it permissible to recite silently during prayer if the worshiper's voice, though low, disturbs those around him?

It is permissible for someone praying alone to recite aloud unless it disturbs others. As for the one praying behind an Imam (Ma'mum), the Sunnah for them is to recite silently. The Imam should forbid reciting aloud behind him during silent prayers, as this goes against the Sunnah and causes disturbance. The Prophet, peace and blessings be upon him, forbade disturbing others, saying: "Do not raise your voices over one another with the Qur'an." Therefore, a worshiper should recite silently, whether they are praying behind an Imam or alone, to avoid disturbing those around them, and because reciting aloud goes against the Sunnah, especially when praying behind an Imam.