Those kinds of words that you learn about in grammar lessons instead of vocabulary lessons often have two sounds in English. The normal one is called the weak form. This is the form we usually use when the word isn't stressed. The other is called the strong form. The word and has a weak form. It sounds like this: /ən/. Notice that this word doesn't have a /d/ sound here.
However, the word /ən/ ends in an /n/-sound. The sound /n/ often changes according to the following consonant. Before /p, b, m, w/ it can become a /m/. Before /k/ and /g/ it can become a /ŋ/. In the original Poster's clip, the word and comes before the word came, /keɪm/. For this reason the /n/ in and has changed to a /ŋ/. What the OP is actually hearing is:
The reason adventure sounds strange is because it deosn't start with an /æ/, the sound we hear in cat it starts with /ə/, the sound at the beginning to the word America.
How do English speakers understand each other when the grammar words change so much? Well, part of the answer is that grammar words aren't actually very important for understanding at all. Native speakers can't understand most unstressed words when they aren't actually in a sentence. To show how easy it is to understand English without hearing the grammar words, think about the following situation. A two year child old comes to speak to you and says:
You will probably understand that they want to go to the park. However if they come to you and say:
You won't understand them at all. These words are all from the same sentence:
- I want to go to the park.
We can understand a sentence mainly from the stressed information words. The grammar words don't make much difference to the meaning, and English speakers often decide what the grammar words are after they understand the sentence, not before! So don't try too hard to hear the grammar words carefully. Listen to the information words instead.