I noticed that the symptom nearly disappears when I put my chin on the chest
and exhale,
and gets much worse when I look above me
and exhale. I tried to pinpoint the origin of this wheezing-rattling sound, and it looks like to be just below the vocal chords. To support this hypothesis, the fact that when I exhale and hear/feel the strange noise, and immediately after try to say a word, the words vibrates closer to the base of the tongue than the strange noise.