Timing and trials of hearing aids and assistive devices

Of all the factors under consideration during the evaluation for a cochlear implant, perhaps the most critical is the speech perception ability of the candidate when using appropriate amplification. For children, this issue is often complicated by inadequate training or limited use of the sensory aid. Guidelines for implantation suggest that there be a ''lack of benefit from hearing aids'' to qualify as a candidate. This ''lack of benefit'' must be explored when using the most appropriate aid coupled with the proper rehabilitation. In determining candidacy for children, it becomes extremely important to assess benefit using a variety of sensory aids while having access to well-directed auditory intervention. The types of amplification that can be used during the preimplant evaluation stage include conventional behind-the-ear devices, FM units, vibrotactile aids, and frequency transposition aids. Although some of these devices are used more often than others, centers implanting children should be aware of the role that each plays in the evaluation process. To determine the frequency with which these devices are used as well as the types of strategies that are emphasized in the preimplant training interval, a questionnaire was developed to gather information from the cochlear implant facilities in the United States. The results of this survey will be presented to demonstrate training and device trends that are incorporated during the preimplant process. Additionally, the use of frequency transposition hearing aids as part of the preimplant training procedure will be explored. The facility at Manhattan Eye, Ear and Throat Hospital has studied these devices in a small group of adults and children. Data pertaining to the speech perceptual abilities obtained with both the TranSonic and the Emily will be presented and compared to results with the Nucleus cochlear implant system.