The following is only my worthless opinion and can be wrong, so please someone correct me.
This makes me think of tranquilizer or a stun gun that make one disabled for a bit. However, Guru Sahib's Shabad, i.e. Gurbani, the updesh of Gurbani is such a thunderbolt that it pretty much cripples one's vikaars permanently. This is what probably Bhagat Kabeer Jee means. The hit of Guru Sahib's Shabad is so massive, he feels "mute", "insane", deaf".
He feels mute because he has nothing left to say (Punjabi phrase - bolti band hogi).
ਹਰਿ ਹਰਿ ਕਥਾ ਬਨੀ ਅਤਿ ਮੀਠੀ ਜਿਉ ਗੂੰਗਾ ਗਟਕ ਸਮ੍ਹ੍ਹਾਰੇ ॥ The sermon of the Lord, Har, Har, is so very sweet; like the mute, I taste its sweetness, but I cannot describe it at all.He feels insane, because for the world anyone drowned in Vaheguru's Love is crazy.
ਹਰਿ ਗੁਨ ਕਥਤ ਸੁਨਤ ਬਉਰਾਨੋ ॥ I have gone insane, chanting and hearing the Glorious Praises of the Lord.
By deaf he probably means that since Guru Sahib's Shabad has hit, nothing else said/heard will have any effect, as now nothing else will work.
ਹੇ ਜਿਹਵੇ ਤੂੰ ਰਾਮ ਗੁਣ ਗਾਉ ॥ ਨਿਮਖ ਨਿਮਖ ਹਰਿ ਹਰਿ ਹਰਿ ਧਿਆਉ ॥ ਆਨ ਨ ਸੁਨੀਐ ਕਤਹੂੰ ਜਾਈਐ ॥ ਸਾਧਸੰਗਤਿ ਵਡਭਾਗੀ ਪਾਈਐ ॥ O tongue, sing the Glorious Praises of the Lord. Each and every moment, meditate on the Lord, Har, Har, Har. Do not listen to any other, and do not go anywhere else. By great good fortune, you shall find the Saadh Sangat, the Company of the Holy.
Please forgive and correct mistakes
ਸਤਿਗੁਰਬਚਨਕਮਾਵਣੇਸਚਾਏਹੁਵੀਚਾਰੁ॥