Translation:I am listening to the lectures about animals.
In fact, yes, you can! Unfortunately, it doesn't always work well in the present tense in English.
I heard a lecture on Trionychidae yesterday.
I'm on my way to hear a lecture on Trionychidae.
Right now, I'm listening to a lecture on Trionychidae.
But it works well in Norwegian!
If you had been translating from English to Norwegian, both "lytter til" and "hører på" would be correct. However, whilst "å høre" translates to "to hear", the addition of "på" indicates that you are hearing something specific, namely the lectures. As a result, you are no longer hearing things, but specifically listening to the lecture, thereby altering the meaning of the verb. :)
Thus, a translation back to english as "I hear at" would be incorrect use of language, as within English, the meaning of the two words (listen/hear) is much more strict.