Acoustic Speaker Identification: The LIMSI CLEAR'07 System

The CLEAR 2007 acoustic speaker identification task aims to identify speakers in CHIL seminars via the acoustic channel. The LIMSI system for this task consists of a standard Gaussian mixture model based system working on cepstral coefficients, with MAP adaptation of a Universal Background Model (UBM). It builds upon the LIMSI CLEAR'06 system with several modifications: removal of feature normalization and frames filtering, and pooling of all speaker enrollment data for UBM training. The primary system uses a beamforming of all audio channels, while a single channel is selected for the contrastive system. This latter system performs the best and improves the baseline system by 50% relative for the 1 second and 5 seconds test conditions.