Alef (also spelled Aleph) is the first letter of the Alefbet, the Hebrew alphabet.

For this letter, imagine a headless man. Ok, a little gruesome, but imagine it anyways. Here's what he'd look like:

So, what does Alef sound like? Nothing. Hence the headless guy. Like a man without a head, Alef doesn't make a sound by itself.

It doesn't sound like anything, in fact, unless it has a vowel sign under it. So now you're thinking, "What about the vowels already? Show me the vowels!"

Right. So on to your first vowel, called Patach.