Does it happen in casual talk that a vowel after ‘an’ is not strongly pronounced?

There was a person that speak “an attaché” but it sounds to me that he pronounce it as “anttaché”, dropping ‘a’ before double t sound.

Question

Does it happen in casual talk that a vowel after ‘an’ is not strongly pronounced?

There was a person that speak “an attaché” but it sounds to me that he pronounce it as “anttaché”, dropping ‘a’ before double t sound.

Answer

The first syllable in 'attaché' isn't really 'a'. It's the shwa sound. All non-stressed vowels are pronounced as the schwa sound. These are not really dropped but they are so unstressed as to be barely heard.

Answer

Yes, in casual speech, especially in rapid or informal conversations, the vowel after 'an' might not be strongly pronounced. It's elision.
Certain sounds are less distinct due to the natural flow in a conversation.

Answer

Claire gave an excellent answer.

Answer

This depends on the accent and the speed at which they are speaking.

At rapid pace, its almost impossible to not drop the 'a'.
At slow pace, it depends on the accent.