Audio on computer displays it's working but no audio is coming through

Well I am only speaking from experience and I have been messing with electronics form the days of vacuum tubes through transistors per se' to small circuitry chips to the beasts we handle today and am excited about the tech that is now involving organics and elements at the atomic level in building components for machines as opposed to pure solid state elemental structures.
One only has to realise the level that smart phones for example are at right now, but assuming you are that much younger than I - do expect technologies that will around long after I am gone will be so much more exciting than I can ever imagine.
Now I can only assume again that you may think I am just another old codger who is preaching for the sake of it but in actual fact I am only trying to pass on my experience to you insomuch as being aware that as much as one might think they know there is always room for a friendly push in the right direction.
For an analogy my father always said no matter how big and talented a boxer might be there is always someone a little but larger or smarter, and by that I am not insinuating you are not smart - probably more than I ever will be.
So just to humour me if you will really research as I said and never make the mistake like I have many times of not doing so and living to regret it.
John:)