Hearing aids in children: the importance of the verification and validation processes.

Abstract

BACKGROUND: during the fitting of hearing aids in children it is important, besides using a verification protocol, to have a validation process. AIM: to describe and discuss the use of a protocol for the fitting and the verification of hearing aids in children, as well as the impact of the adjustment of the acoustic characteristics in speech perception tasks. METHOD: ten children aging from three to eleven years were enrolled in this study. All children presented bilateral sensorineural hearing impairment, were users of hearing aids and were followed at a public hearing health care service in Bahia. The children were submitted to the following procedures: pure tone air and bone conduction thresholds; real-ear coupler difference (RECD); verification with real-ear measurement equipment: coupler gain/output and insertion gain and to speech perception tasks: "The Six-Sound Test" (Ling, 2006) and the "Word Associations for Syllable Perception" (WASP - Koch, 1999). The programmed electro acoustic characteristics of the hearing aids were compared to the electro acoustic characteristics prescribed by the DSL [i/o] v4.1 software. The speech perception tasks were reapplied on three occasions: straight after the modification of the electro acoustic characteristics, after 30 days and 60 days. RESULTS: for more than 50% of the tested children, the programmed electro acoustic characteristics of the hearing aids did not correspond to that suggested by the DSL [i/o] software. Adequate prescription was verified in 70% of the investigated sample; this was also confirmed by the results in the speech perception tasks (p=0.000). This data confirmed that the mean percentage of correct answers increased after the modification of the electro acoustic characteristics. CONCLUSION: the use of a protocol that verifies and validates the fitting of hearing aids in children is necessary.