Pattern Help Needed

Hi, I am a fairly experienced knitter, but am used to patterns in a different language than English. This is the first time I am following an English pattern. I am knitting a cable sweater and have figured out the pattern, but now I find myself stuck at the armhole decrease. Could some one please clarify for me how to read:
"Dec 1 st each end of needle on next 7 rows". Does this mean I am knitting to the end of each needle and decrease by one, repeat 7 times, OR decrease at the beginning of the row by one and at the end of the row by on for the next 7 rows - this would really be two stitch decrease on each side at a time, correct? The pattern then continues to "then on following alt rows until there are 80 sts".
Help please. I started knitting the front now and am waiting for help with the back armhole shaping.