I've heard /ˈtaʊə/. But at elementary and pre-intermediate level it's really difficult to hear the words correctly.

Hi Irina, I agree with Hamed - the narrator clearly says /ˈtaʊə/, but the diphthong is quite smooth. If he'd said /ta:/, we'd hear a very flat vowel sound.

Thank you, @merlyn. It's really encouraging to hear that.

that's no problem Iris, many people pronounce tower with the w and and also hour with a w , it is a natural way to say it, both in America and Britain.

By the way, I've just realised that I pronounce "hour" with "w" as well.