There are many factors that influence speech intelligibility. These factors may reside within the speaker, the listener, the context, or the environment. Because of the broad nature of this concept, we often prefer the more inclusive term of comprehensibility.

When we assess intelligibility, we do so at the word, sentence, and discourse level.

Supplemental assessment can also be conducted through instrumentation. For example, the Computerized Speech Lab (CSL) can provide information about pitch and loudness. In addition, we use a particular program called the Motor Speech Profile available on the CSL.