Because in different dialects the feminine articles and declensions are used in varying degrees.

In some dialects feminine inflection and articles are (or are almost) completely abandoned in favor of common gender (feminine nouns are treated as if they were masculine). In other dialects the feminine forms are used more.

In written language you can also choose whether you want to use the feminine forms or not.

Have a look at this part of the wikibook on norwegian: https://en.wikibooks.org/wiki/Norwegian/Lesson_2#Gender_of_Nouns

All nouns are either M, F or N, and these are just to memorize. In Norwegian Bokmål it's optional to use "en" [M indefinite article] instead of "ei" [F indefinite article]. In Norwegian Nynorsk though, you can't.

For a feminine noun, you can choose whether to use the masculine or the feminine article "en or ei". "Jente" is a feminine Norwegian noun, it’s correct to say both "ei jente" and "en jente". This only applies to feminine nouns.

If you cant hear the difference use context. 'Jente' will almost always have a word like 'ei' or 'noen' or somthing else to show it is indefinite- ei jente/a girl noen jente/any girl. "Ei jenta" would mean "a the girl" sounds as bad in Norwegian as it does in english

I'm remarkably hopeless as hearing the difference between "jente" and "jenta". I would like to be able to hear them back to back but haven't found that option yet.

http://no.wiktionary.org/wiki/jente

Does this table explain it to you?

In contrast to German, however, these articles are fixed. E.g. it's always en and -en, not like in German either ein, einen or einem / der, den or dem. But yes, like most languages with genders, you'll have to memorize it.

The word jente is of feminine gender but can take the masculine indefinite article en as well.

Please refer to @En-tyskr-i-Norge's reply on this page for more info.

In a listening exercise, you have to input what you've heard and not what you usually associate with that particular word (Barnet er ei jente vs. Barnet er en jente) and everything will work smoothly.

In all other cases, en jente and ei jente are equally correct which means the application should accept both variants.

"Jente" is the indefinite singular. Any unspecific girl is "en / ei jente" = "a girl".

"Jenta" is the definite singular. Any specific girl is "jenta" = "the girl".

• "A girl is reading a book" = "Ei jente leser ei bok"
• "The girl is reading a book" = "Jenta leser ei bok"

Female nouns are usually "ei": "Ei jente", "ei bok", "ei flaske". But they can also use the male form "en": "En jente", "en bok", "en flaske". Some Norwegian regions / dialects insist on using the female forms, others don't.

I promise I am not following you and telling you what you should hear but TTS is not at fault here either. Look at the graph below to see how close ɑ (open back unrounded vowel) is to ə (mid central vowel).

Although the current match result is 0:2, I'm sure that you'll end up striking those goals as you become more and more surrounded by the language itself and exposed to its sounds. Give your ears time and it will click in your mind. Also, we are always here when people need help.