In speech synthesis, an **objective test** is a methodology to evaluate the performance of [[what is speech synthesis|speech synthesis]] systems using specific criteria to measure the quality and accuracy of the synthesized speech without involving human listeners. Objective tests in speech synthesis typically involve comparing the synthesized speech to a reference or target speech. The tests focus on evaluating specific aspects of the synthesized speech, such as its intelligibility, naturalness, similarity to the reference, or the accuracy of certain linguistic or acoustic characteristics. Some commonly used objective tests include [[perceptual evaluation of speech quality (PESQ)]], [[mel cepstral distortion (MCD)]], and [[word error rate (WER)]].