I know the difference in written (Tochter vs Töchter), still hard listening to it. I can recognize the difference in Vogel vrs Vögel, Schon v Schön. But this in particular audio of the robot woman saying "Die Töchter" I can't distinguish it from "Die Tochter" (the male voice saying "Tochter" is really clear)
Try Dutch,you'll see a lot of similiarities.And naturally the English language changed over the course of time,and it had influence from non-Germanic languages as well.I'm doing Swedish,German and Dutch,and i can't believe how many similiarities they have. You have to take into account that modern English differs greatly to Old English,plus there are many archaic words that you'd find to be quite similiar to equivalents in other Germanic languages.
Der Mann, die Männer; the man, the men. English does umlauts too, but they can be a bit disguised. Woman, women. The ö sound in Töchter is found in French "peu, meuble" and British English "fur, fir"
Ä = English soind in "air" Ö = English sound in "fur, fir" Ü = is closer to French "mur". Try saying a long English EE while making and holding an OO shape with your lips. Feels silly, but it works.