Conure no vocal only giving weird sound

[sparky_09]

I bought 2 sun conures two weeks back one male and one female. Both used to be highly vocal at starting but for the past week only female conure is vocal and the male is not even giving a single sound. He is playful, preening, eating, standing in one leg and doing everything except the vocal.

He is giving a low sound which only looks like he is letting out air. I already took him to a vet and his temperature is 107 F, and put him in antibiotics Toxo Mox which I have been giving him for past two days. Please help