Normative data for the Maryland CNC Test.

BACKGROUND

The Maryland consonant-vowel nucleus-consonant (CNC) Test is routinely used in Veterans Administration medical centers, yet there is a paucity of published normative data for this test.

PURPOSE: The purpose of this study was to provide information on the means and distribution of word-recognition scores on the Maryland CNC Test as a function of degree of hearing loss for a veteran population.

RESEARCH

DESIGN

A retrospective, descriptive design was conducted.

STUDY SAMPLE: The sample consisted of records from veterans who had Compensation and Pension (C&P) examinations at a Veterans Administration medical center (N = 1,760 ears).

DATA COLLECTION AND ANALYSIS: Audiometric records of veterans who had C&P examinations during a 10 yr period were reviewed, and the pure-tone averages (PTA4) at four frequencies (1000, 2000, 3000, and 4000 Hz) were documented. The maximum word-recognition score (PBmax) was determined from the performance-intensity functions obtained using the Maryland CNC Test. Correlations were made between PBmax and PTA4.

RESULTS

A wide range of word-recognition scores were obtained at all levels of PTA4 for this population. In addition, a strong negative correlation between the PBmax and the PTA4 was observed, indicating that as PTA4 increased, PBmax decreased. Word-recognition scores decreased significantly as hearing loss increased beyond a mild hearing loss. Although threshold was influenced by age, no statistically significant relationship was found between word-recognition score and the age of the participants.

CONCLUSIONS

RESULTS from this study provide normative data in table and figure format to assist audiologists in interpreting patient results on the Maryland CNC test for a veteran population. These results provide a quantitative method for audiologists to use to interpret word-recognition scores based on pure-tone hearing loss.