голоса их были слышны, но нельзя бы

голоса их были слышны, но нельзя было разобрать, о чем они говорят.

Результаты (английский) 1:

their voices were heard, but it was impossible to make out what they are talking about.

Результаты (английский) 2:

their voices were heard, but could not make out what they were saying.

Результаты (английский) 3:

Their voices were heard, but they should not have been disassembled, what they are talking about.