Faulty formulation: Because the Qur'an is read through a human voice, it should be treated as something authored by the reciter.
Correct formulation: The Qur'an is the speech of Allah; the reciter's voice, articulation and act of recitation are human acts. The origin of the speech is different from the act of reciting it.
وَإِنَّ الْقُرْآنَ كَلَامُ اللَّهِ
The Qur'an is truly the speech of Allah.
Application: Whether someone's recitation is melodious or weak does not change the divine origin of the Qur'an.