It's more similar to the "e" in "get", but lengthened. It is certainly not a diphthong as most English speakers would use in saying "they".
But really, English vowels are not much help to us in speaking romance languages. It is best to look to Italian: if you can imitate those vowel qualities, you are well placed to pronounce Latin well.
The right pronunciation is hăbēs. One of the speakers tends to lengthen stressed vowels, though there is no correlation between stress and length in classical Latin.
Edit: I meant that the length of a vowel does not depend on stress (as in Italian for instance where stressed vowels are lengthened). A vowel is short or long, it does not matter whether it is stressed or not. On the other hand, the placement of stress depends on syllable length, wich itself depends on vowel length.
Yes, that was the kind of understanding I got from a few other sources. Since I'm here to learn not only grammar and vocabulary but pronunciation as well, it is hoped that the course gets improved with respect to the latter. If we get accustomed to "wrong" pronunciation as beginners, it might not be as easy to correct ourselves at a later stage. It appears to me that the speakers in the recordings tend to ignore, on purpose or otherwise, differences in length vowels and consonants. Hopefully, this course will stick to the principle clearly stated in the Pronunciation section of the tips for Introduction: "This course uses Classical Pronunciation".
Again. I know the course is made by Duolingo users, and I appreciate it, but really guys, you couldn't think of any more sentences than "You have a strict mother" and "She is also a mother"? I know, repetition is necessary and all, but so is variation. "You have an extraordinary aunt.", "My uncle is a powerful man." "Is your cousin in the senate?" C'mon, it's not that hard to come up with a few more examples...