Perceived liveliness and speech comprehensibility in aphasia: the effects of direct speech in auditory narratives

Background: Previous studies have shown that in semi-spontaneous speech, individuals with Broca's and anomic aphasia produce relatively many direct speech constructions. It has been claimed that in 'healthy' communication direct speech constructions contribute to the liveliness, and indirectly to the comprehensibility, of speech.

Aims: To examine the effects of the occurrence of direct speech constructions on the perceived liveliness and speech comprehensibility of narratives produced by individuals with and without aphasia.

Methods & Procedures: Thirty-seven naive listeners rated 30 speech fragments with and without direct speech from ten speakers with and ten speakers without aphasia. The fragments originated from semi-structured interviews. The raters scored the perceived liveliness and the perceived comprehensibility of these fragments.

Outcomes & Results: For both groups of speakers, fragments containing direct speech constructions received higher scores for liveliness than fragments without direct speech constructions. However, no effect of direct speech was found on perceived comprehensibility.

Conclusions & Implications: This is the first research to demonstrate that communication is perceived as more lively when it contains direct speech than when it does not, but yet is not more comprehensible. Individuals with Broca's and anomic aphasia are known to produce regularly direct speech constructions in elicited narratives. Given that liveliness is known to increase listeners' involvement and to help listeners stay focused, we suggest that this relative increase in direct speech by aphasic speakers may reflect a strategy to increase not only the liveliness of their discourse, but also listener focus and involvement.