Past studies have shown evidence of important speaker-specific content in the higher frequencies of the spectrum, which are filtered out by narrowband channels. Besides, wideband transmissions, which are gaining ground over narrowband communications, offer an extended range of frequencies which account not only for better speech quality and intelligibility, but also for an improved speaker recognition performance. In this work, different phoneme classes (fricatives, nasals, and vowels) were removed from speech of different bandwidths, and a series of i-vector based speaker verification experiments were conducted. Our results show that the performance enhancement with clean wideband speech with respect to clean narrowband speech is principally due to the presence of unvoiced fricative consonants. The effects of codec schemes of different bandwidths on the aforementioned speech are discussed.
Bibliographic reference. Gallardo, Laura Fernández / Wagner, Michael / Möller, Sebastian (2014): "I-vector speaker verification based on phonetic information under transmission channel effects", In INTERSPEECH-2014, 696-700.