Rule reminder
English and Italian cleft sentences share the same basic function (emphasis through splitting) but differ in structure: English: 'It is + [focus] + that/who + clause'. Italian: 'È + [focus] + che + clause'. Key differences: (1) Italian 'essere' agrees in number with the focused element; English 'it is' never changes. (2) Italian uses only 'che' (or 'a + infinitive'); English uses 'that', 'who', 'which'. (3) The pseudo-cleft in English: 'What I need is...' → Italian: 'Quello che mi serve è...' or 'Ciò che mi serve è...'
Translate: 'It is her voice that I recognise.'