Effect of background noise on the SNR estimation of biometric parameters in forensic speaker recognition

In the field of automatic or semi-automatic speaker recognition, background noise is one of the main causes of alteration of the acoustic indexes used in the biometric identification/verification phase. The paper analyses the varying effect of background noise on the first three formants, i.e. the biometric indexes typically used in forensic speaker identification. The analysis is performed by calculating the signal to noise ratio (SNR) in the sub-bands relating to the first three formants with varying vowels and types of noise. The results obtained indicate that background noise has a different impact according to the vowel and single formant involved.