In a study by Schmitt (1969) using 48 deaf participants from ages 8 to 17, it was found that many deaf adolescents as late as age 17 had problems comprehending reversible passive voice constructions. Schmitt concluded that they probably ignored the passive voice markers, that is, the verb to be and the by-phrase, and interpreted the sentences as active voice constructions. In other words, after reading a sentence like “The girl was pushed by the boy”, a deaf adolescent might often think that the girl pushed the boy--the absolute opposite interpretation to the one intended.
Power and Quigley (1973) studied 100 prelingually profoundly deaf children between ages 9 and 18. Their research supported the findings of Schmitt (1969). They believed that the deaf children were processing the subject-verb-by-phrase of a passive sentence as if it were subject-verb-object of an active voice sentence. And they named this kind of processing subject-verb-object (or SVO) reading strategy.
They further noticed a hierarchy of difficulty, as follows:
- The most difficult were the agentless passive constructions, like "The child was washed,"where the by-phrase was missing and only the verb to be with the past participle appeared as an indicator of the passive voice.
- Of only slightly less difficulty were reversible passive constructions like “The girl was pushed by the boy,” which participants often interpreted as “The girl pushed the boy.”
- Of least difficulty were the nonreversible passive constructions such as “The car was washed by the man,” where an SVO reading strategy would have produced a nonsensical meaning.
Both the study by Schmitt and the study by Power and Quigley had presented their participants with passive voice constructions in isolated sentences. However, a third study by McGill-Franzen and Gormley (1980) presented 36 deaf elementary school children with passive voice constructions both in isolation and then embedded in context-rich connected prose. Their participants demonstrated significant improvement in the comprehension of the passive voice sentences that were embedded in connected prose.