The 'aa' as in 'bat' Vowel

If you want more information on the photos in this video, which have parts of the mouth drawn in, see this video on the parts of the mouth.
How to make this sound:

The audio is now available for download thanks to user Slava from Cherkessk, Russia: Download mp3
Video Text:

The 'aa' as in 'bat' vowel sound.  To make this sound, the tongue stretches up in the back, aa, towards the soft palate and roof of the mouth, aa.  The front of the tongue stretches forward and presses here behind the bottom front teeth, aa.  And the tongue sort of flattens wide, aa, aa.  Because the tongue is raising and then coming forward, you can see a lot of tongue, aa.  This is different from the 'ah' as in 'father' vowel, for example, ah, where the tongue is pressing down and you see more dark space in the mouth.  Ah, aa.  You can also note the corners of the mouth are pulling back a little, aa, exposing some of those top teeth, aa.

Here is the 'aa' as in 'bat' vowel sound on the right compared with the mouth at rest on the left. Here the inside parts of the mouth are drawn in. Notice that, as with all vowels, the soft palate is raised. But more importantly, note the difference in tongue position. In the 'aa' as in 'bat' vowel, the tongue is raised and pulled up in the back, towards the throat and soft palate. However the front of the tongue is still touching behind the front bottom teeth. Sample words: habit, apple, blast, that. Sample sentence: The master gardener now, sadly, has a bad back.  Now you'll see this sentence up close and in slow motion, both straight on and from an angle, so you can really study how the mouth moves when making this sound.

The, tongue comes through the teeth for the TH. Lips together for the M, and here is the 'aa' as in 'bat', ma-, you can see the top lip a little raised. Rr, the R sound, the master gardener, the 'ah' as in 'father' mixed in with the R. Gardener. Tongue up to make the N. Now, with the 'ow' as in 'now' diphthong. Sadly, teeth together to make the S. And here is another 'aa' as in 'bat' sound. Sa-, the jaw drops, you can see the top teeth, the lips is a little pulled up for it. Tongue up for the D, and down, 'ee' as in 'she', sadly. Has, another 'aa' as in 'bat', you can see the tongue is spread very wide in the back. A bad, lips together for the B, another 'aa' as in 'bat'. You can see again the top lip is pulled a little bit. Back. Again, the 'aa' as in 'bat' sound.  Here from an angle:

The, tongue tip through the teeth for the TH. Master, lips together for the M. Here is the 'aa' as in 'bat', see the tongue is raised more in the back. Master, the R consonant shape. Gardener, 'ah' as in 'father' mixed with the R consonant sound. Tongue tip up for the D and the N. Now, tongue comes down from the N into the 'ow' as in 'now' diphthong. Sadly, teeth together for the S. And here is another 'aa' as in 'bat' sound. The tongue tip down by the bottom teeth, raised in the back. Tongue tip up for the L. Sadly, pulled wide for the 'ee' as in 'she'. Has, another 'aa' as in 'bat' sound. A, the schwa, bad, lips together for the B, the 'aa' as in 'bat', you can see the tongue is really stretched from forward to back. Back, again, the stretched tongue raised in the back. Then it raises more in the back and touches there to make the kk consonant sound. That's it, and thanks so much for using Rachel's English.

Tomado de http://www.rachelsenglish.com/vowel_aa_bat