Harsh sound coming from vocal chords

[Peppe271]

Hello, since April i am suffering from a strange condition. When I exhale strongly, I hear like a whirr sound coming from where my voice box is. It changes intensity if I move the head and exhale, being the minimum (or disappearing) as long as i touch my chest with the chin. When I am able to reproduce the sound, my voice will be down as If i were  heavily smoking, and coming back to normal after a few seconds and after a few coughs to clear the throat. I always have a feeling like I was about to cough mucus, which is not there. I had several (3) ent visits, without endoscopy, a bronchoscopy and a ct of lungs, all negative. I suffer from heartburn, which I control with medicines such as omeprazolum. I am a very rare smoker (such as three or four cigarettes a month) but whenever I smoke, since this happened first, I get a very bad dry cough. Also, just before this happened first, I was smoking a lot the electronic cigarette, just for pleasure. I have done also cultivation of sputum, also negative. Could you please suggest me what do now, what kind of examination to undergo? I don't think it is a really serious thing, but sometimes i feel that my breathing is a bit impaired, although a spirometry was negative. A note of mention, i weight 118 kg for 186 cm of height.