First, let's start by comparing profile pictures of the two sounds.

Here you'll see the EH as in BED vowel on the left, and the AA as in BAT vowel on the

right. For the AA vowel, you can see that it's the back part of the tongue that raises

up towards the roof of the mouth. For the EH vowel, it's the mid/front part of the tongue

that is stretching up. Also, for the AA, you can see that the jaw drops just a little bit

more.

So, for the AA vowel, the tongue is raising here. AA. And for the EH vowel, the tongue

is raising more here. EH. So, here for the AA and here for the EH.

AA, EH. When comparing the two sounds in isolation, you'll also notice that the jaw does not drop

as much for the EH sound, as the front part of the tongue is raising towards the roof

of the mouth. AA, EH.

There's a difference in the lip position as well. For the AA vowel, you may find that

you get a more accurate sound if you lift a little bit here with the top lip. AA, AA.

Whereas, for the EH sound, the lips remain very relaxed and neutral, EH, EH. Now we'll

see the two alternating up close. AA, EH, AA, EH.

To close, a few minimal pairs. Bat, bet. Capped, kept. Jam, gem. Tack, tech. Rack, wreck.

I hope this video has made the difference between these two sounds a little more clear.

That's it, and thanks so much for using Rachel's English.