i hear a T-sound after مَلِكة . Is it actually there or is there a mistake in the audio?
Yes. The audio is correct.
The word ملكة (queen) ends with Ta'-Marbúta تاء مربوطة which is a letter combining "H" and "T".
In isolated position or at the end of the sentence, this letter would sound as (H), but when moved with a vowel (for any reason), as in this instance, the "H" changes to "T". Here, the word (Malikah) changed to (Maliktun), the last -un sound is called Tanwin (or Nunation) which is one marker for indefinite noun in Arabic (could be considered so). Since we need Tanwin on this word because it is indefinite, the H has been changed to T.