The overall intelligibility of speech is rated on a five-point scale to specify how well the speaker can make his or herself understood when reading the Rainbow Passage aloud.
| Rating | Comments | Sample |
|---|---|---|
| Level 1 | Speech is completely unintelligible. In this example, speech is unintelligible with single syllable utterances. However, the speaker has fairly good control of pitch. | (Female) |
| Level 2 | Speech is very difficult to understand-only isolated words or phrases are intelligible. In this example, occasional words and phrases are intelligible, but in general, the content of the message cannot be understood. Deviate respiration during speech, pitch breaks, and abnormal prosodic features are evident. Syllables are sometimes arrested at the level of the glottis. | (Male) |
| Level 3 | With difficulty, the listener can understand about half the content of the message (intelligibility may improve after a listening period). In this example, the general content of the message can be understood although the listener has some difficulty. Numerous articulation errors are evident in addition to faulty coordination of respiration and laryngeal function. Many initial sounds within breath groups are over-aspirated. Loss of breath and tone support for final sounds within words and phrases is also evident. | (Male) |
| Level 4 | Speech is intelligible with the exception of a few words or phrases. For the most part, in this example, speech was intelligible; however a few words such as 'ever, above, reach,' could not be understood. | (Male) |
| Level 5 | Speech is completely intelligible. A rating of V does not indicate perfect articulation and/or normal quality, but rather speech wich is completely intelligible. In this example, the speaker did have slight distortions of /s/ and /z/, but these distortions did not interfere with the intelligibility of the message. | (Male) |