A limited number of tests, older as well as more recent ones, are described in detail below. The first 8 pertain to intelligibility tests, ordered from tests based on meaningless items of a few phonemes to tests based on meaningful sentences, 9 and 10 describe two prosody tests, and, finally, 11 and 12 are related to two overall quality tests. Tests were included that have been frequently used, or were developed specifically, for evaluating synthesis output. Four tests (SAM Standard Segmental Test, Cluster Identification Test , Semantically Unpredictable Sentences, and the SAM Overall Quality Test ) were developed within the ESPRIT-SAM (Speech Assessment Methods) project (1989-1992). With the exception of CLID , software for these tests is available in SOAP (Speech Output Assessment Package) [Howard-Jones (1992a)]. SOAP also includes programs to add noise to speech files, to automatically generate test sequences, to randomise test sequences, and to equalise speech levels . Test descriptions are given below; further current information can easily be found by standard Internet search methods.