Rev 5:11
And I beheld, and I heard
the voice of many angels round about the throne and the beasts and the elders: and the number of them was ten thousand times ten thousand, and thousands of thousands;
Rev 5:12
Saying with a loud voice, Worthy is the Lamb that was slain to receive power, and riches, and wisdom, and strength, and honour, and glory, and blessing.
So you wanna take away angels' vocal cords?
Angels are pictured in Revelation doing things that they could do here on earth like they did when they were sent -- in fact, they READ in Revelation -- all of the seven letters to the churches in Asia are written TO the ANGELS of each church.
The fact that Revelation is a VISION does not mean angels are pictured doing things that they cannot do in reality.
The fact that Paul spoke in hyperbole in the passage "Although I speak with the tongues of men and of angels" does not mean that angelic language does not exist. He infers the possibility that it DOES exist.
Dan 10:12
Then said he unto me, Fear not, Daniel: for from the first day that thou didst set thine heart to understand, and to chasten thyself before thy God, thy words were heard, and I am come for thy words.
Dan 10:13
But the prince of the kingdom of Persia withstood me one and twenty days: but, lo, Michael, one of the chief princes, came to help me; and I remained there with the kings of Persia.
We infer that Gabriel and Michael can COMMUNICATE with each other -- why would they use a HUMAN language to do that? They have been around before humans were.
Angelic language exists, forbid not the angels from using their vocal cords, as you forbid not those of us so gifted to pray in tongues - that may well be a heavenly language also.