1. A text-to-speech learning system, the system comprising: at least one processor; and memory, operatively connected to the at least one processor and storing instructions that, when executed by the at least processor, cause the at least one processor to perform a method for generating a pronunciation sequence conversion model, the method comprising: generating a first pronunciation sequence from a speech input of a training pair; generating a second pronunciation sequence from a text input of the training pair; determining a pronunciation sequence difference between the first pronunciation sequence and the second pronunciation sequence; and generating a pronunciation sequence conversion model based on the pronunciation sequence difference.