3 times over recent months head people call me, twice hello, one my name, loudly enough for me to respond, current depression, any cause for concern?

Hearing 'voices': There can be many reasons for hearing 'voices' which vary re concern, eg., acute or complicated grieving, loneliness, triggers of past trauma, anniversary reactions. Since you say you're depressed, why not see a mental health professional who can get to know you and better assess the meaning or cause of your hearing people calling you recently. Ask your pcp for a referral. I hope this helps.