To speak effectively, an individual must be able to produce speech that can be heard, understood, and sustained well enough to permit useful communication in social and vocational settings. These criteria are applicable to the production of speech whether by natural function of the voice mechanism or by the use of a prosthetic device.

Three attributes of speech pertinent to the evaluation of speech proficiency are: (1) audibility — the ability to speak at a level sufficient to be heard; (2) intelligibility — the ability to articulate and to link the phonetic units of speech with sufficient accuracy to be understood; and (3) functional efficiency — the ability to produce and sustain a serviceably fast rate of speech output over a useful period of time. When at least one of these attributes is missing, overall speech function is not considered effective.

When a refined assessment of speech proficiency is necessary, it should be made by an otolaryngologist or a speech therapist whose evaluation should be based both on personally listening to the claimant's speech and on a history of the claimant's performance in everyday living. The findings should be sufficient to provide the reviewer with a clear picture of the individual's speech capacity. Such an analysis covering the attributes of speech discussed above would include a detailed description of the following points:

1. 1. 

   The intensity of speech (audibility) — the conditions under which the individual can and cannot be heard (e.g., in quiet surroundings, noisy places, a moving automobile); the maximum distance at which individuals can be heard; whether their voices tend to become inaudible, and if so, after how long;

2. 2. 

   The ability to articulate (intelligibility) — the frequency of any difficulties with pronunciation, the extent to which the individual is asked to repeat, how well the individual is understood by strangers unaccustomed to hearing esophageal speech; and

3. 3. 

   The rate of speech and the degree of ease with which the individual's speech flows (functional efficiency) — how well the individual is able to sustain consecutive speech; the number of words spoken without interruption or hesitancy; whether the individual appears fatigued, and if so, after how long.

If medical considerations alone are not determinative of the issue of disability for a title II worker or childhood disability claimant or for a title XVI claimant age 18 or older, consider the individual's vocational factors (age, education, training and work experience) as these factors relate to the ability to perform past relevant work or any other work.