Identification of twins from pure (single speaker) and hybrid (fused) syllables: an acoustic and perceptual case study.

This study describes a speaker-identification task carried out using two sets of single monosyllables and two sets of hybrid monosyllables prepared from monosyllabic words spoken by a set of monozygotic twins. The task was carried out by 6 listeners who were all very familiar with the twins and by the twins themselves. The identification scores for the pure syllables showed that both twins were identified with accuracy above chance; however, the percentage scores were less than perfect in both cases (71.4% and 72.9%). Analysis of the identification scores for the hybrid syllables showed that listeners had difficulty in attributing the hybrid syllables to a single twin. This was confirmed by the lack of significance in three binomial tests. The pure syllables were analysed acoustically to obtain a set of acoustic parameters for each twin. The results of the perceptual study are discussed with reference to the acoustic parameters. In addition, the implications of the study for issues in speaker identification are considered.