Leiter devised an experimental edition of the test in 1929 to assess the intelligence of those with hearing or speech impairment and with non English speaking examinees. This test purports to "provide a nonverbal measure of general intelligence by sampling a wide variety of functions from memory to nonverbal reasoning."[1] A remarkable feature of the Leiter scale is that it can be administered completely without the use of oral language, including instructions, and requires no verbal response from the participant.