If you heard something like "uvoot" , two things are going on: 1) Both English v and Russian v are voiced consonants (meaning the vocal cords are active during their pronunciation). But in Russian, the voice kicks in earlier, giving the impression of a bit of vowel sound before the v. 2) After the v, leading in to the o vowel, there is a moment of what is called labialization, i.e, the lips form to give a slight "oo" sound. Compare Russian "vot" and English "vote" -- there's a big difference.
I don't think you can use вот that way, I think you'd be more likely to use эта for phone calls because вот means more something along the lines of 'behold'.
You can say "вот мама" to a baby showing it its mom. I hardly can imagine any more situations when you say it. And it seems to me that "this is mom" would be better translation.
"Вот" also is used in exclamations: "вот (я/ты) дурак!" (I am/you are so stupid!), "вот, смотри!" (hey, look!). Or when you ask someone (your son for example) to buy you something you can give him money and say "вот (тебе) деньги, пойди купи хлеба". Here it has meaning "take", used when you point at something.
"Здесь" (or less formal "тут") just means "here". If you say phrase above: "здесь деньги, пойди купи хлеба" you either emphasize the place where you put money (e.g. on the table) or emphasize the exact sum "здесь 50 рублей, пойди купи хлеба".
You can say "здесь холодно" (it is cold here) or "вот здесь холодно!" just to stress it emothionally. "Вот" word in this phrase isn't related to your current position because you may say "вот на Аляске холодно!" too.
Sorry if that explanation is too complicated. Never though about these words and nuances are so fine. Native speaker here.
Who is your mom? Who mom is yours? - Here is mom. http://livepixel.org/wp-content/uploads/2015/04/47.jpg
Where is your mom? Where mom is yours? - Mom is here. http://s773.photobucket.com/user/kadmy/media/Stalin_Line/KD8_0966-1.jpg.html
akadji wrote right.
Here is mom. Вот мама. Эта женщина является мамой. Отвечает на вопрос Кто или Которая женщина является мамой.
Mom is here. Мама вот. Мама находится здесь. Отвечает на вопрос Где Место где находится мама.