Speech and Language Understanding (SLU) 5 ECTS Prüfung 2021-10

• Subject: Speech and Language Understanding (SLU) 5 ECTS, Summer semester
• Examiner: Prof. Andreas Maier
• Evaluation
  • Atmosphere was quite relaxed
  • Prof. Maier gives hints in the lecture what is important!
  • Very helpful to watch the videos/visiting the lecture.

* Summarize the lecture

Mind Map

* Short overview about how do we percieve sounds & produce sounds?

Description of ear / Fants Source Filter

* About phonetics and phonemes, major classes and how do they look in the spectogram?

Vowels, Fricatives, Plosives, Nasaln, Laterals…

* How to compute MFCCs?

We have a signal, window it - calculate power spectrum - use Mel Filterbanks (25) - log - discrete cosine transform - use first 12 features. (Replace 0 frequency with energy of the signal)

* Some follow up questions e.q. why windowing, why do the Filterbanks look like that.

FT for pariodic signals; window allow us to interpret the short time as periodic.
Filterbanks design inspired by the Cholea

* Talked about N-Grams (Zerogram, Monogram, etc. - Smoothing Backoff strategies)

* Explain Categories, how can they be used.

* Next question about Speaker Identification

Explained UBM - GMM & MAP

* Whats the difference between UBM + MAP & GMM for every Speaker with EM

* Last question: What is your favourite DL approach and explain it

LSTM - made the drawing and explained it