(DS9 fans will get the paraphrase of an excellent Season 7 episode!)
My speaking voice isn't that hot. I've discovered that there is a slightly sibilant tone, and I sound way more 'Esturary' than I thought. The reason I've suddenly realised this is that I have been recording a podcast covering Non-Sport trading cards (one of my many collecting/hoarding activities!)
I suspect this is something that happens to everyone the first time they hear a recording of their voice - I had the idea that my voice was posher, clear and well enunciated; now I understand why some people have problems understanding what I say!