Listening in to any conversation, one will quickly realize that people don't always know what they are going to say when they start speaking. This causes them to say things like "ummm," "uhhh," or "ahhh." Each of these have their own nuances in usage in English, but many are found in other languages (whilst in Italy one summer, I frequently heard "ahhh" used in a similar manner as that found in English). Another interjection with its own nuances is "huh." This is either used as an extremely passive acknowledgement of something one has heard or found interesting, or as an interrogative when one does not understand a concept. This question about conversational softeners (specifically this comment) was what inspired this question, as oftentimes these interjections are used as conversational softeners themselves. These interjections are hardly ever written out in formal writing, and are hardly words like the ones discussed in the answers to the linked question. So, (see what I did there?) what would be the Latin equivalent of these interjections? Most are just vowel sounds, and might not be language specific, but I would still be interested in knowing whether or not instances of their usage exist.
Here are some common English interjections of the type I have discussed, and their definitions:
um- used as an expression of doubt, hesitation, deliberation, interest, etc.
uh- used to indicate hesitation, doubt, or a pause
ah- used as an exclamation of pain, surprise, pity, complaint, dislike, joy, etc., according to the manner of utterance
huh- used as an exclamation of surprise, bewilderment, disbelief, contempt, or interrogation
hmm- used typically to express thoughtful absorption, hesitation, doubt, or perplexity
eh- an interrogative utterance, usually expressing surprise or doubt or seeking confirmation
er- used to express or represent a pause, hesitation, uncertainty, etc.