I-vector / x-vector
Definition
Fixed-length mathematical representations of a speech utterance used in automatic speaker recognition. I-vectors are derived from Gaussian mixture model statistics; x-vectors are embeddings learned by a deep neural network. Both are scored by a PLDA back-end.
Related terms
- Forensic speaker comparison
- A systematic examination comparing acoustic and phonetic features of a questioned voice recording against known reference recordings of a named individual, expressed...
- Formant frequencies
- Resonance frequencies of the vocal tract that shape vowel quality. F1 and F2 (the first and second formants) are the most informative...
- IAFPA
- International Association for Forensic Phonetics and Acoustics: the primary professional body for forensic phoneticians and audio analysts, which publishes guidelines on speaker...
- Likelihood ratio (LR)
- The ratio of two conditional probabilities: the probability of the observed evidence given the prosecution's hypothesis (same source), divided by the probability...
- PLDA (Probabilistic Linear Discriminant Analysis)
- A statistical back-end model used with i-vector and x-vector systems to compute a similarity score between two utterance representations, normalised for within-speaker...
Explained in
- Speaker Comparison: Methods and the Expert's RoleFixed-length mathematical representations of a speech utterance used in automatic speaker recognition. I-vectors are derived from Gaussian mixture model statis...