Indeed, the worst of living creatures in the sight of Allah are the deaf and dumb who do not use reason.
The Saheeh International Quran Translation
إِنَّ شَرَّ ٱلدَّوَآبِّ عِندَ ٱللَّهِ ٱلصُّمُّ ٱلْبُكْمُ ٱلَّذِينَ لَا يَعْقِلُونَIndeed, the worst of living creatures in the sight of Allah are the deaf and dumb who do not use reason.