They're considered fillers that mark a continuance on part of the speaker so that the other participants know that they will continue speaking. Different languages not only use different sounds, but in many cases continuation markers can also be "normal" words from the language. In English some examples would be "well", or "yes" which can be pure filler words to bridge to the next utterance.
That being said, what is a word anyways? You could argue that they're well understood units of language that convey meaning, which I would argue is pretty much a word
That being said, what is a word anyways? You could argue that they're well understood units of language that convey meaning, which I would argue is pretty much a word