Assessment of the hearing aids' contribution on the auditory neuropathy spectrum: a case study

Abstract

Ojective: This study verified the contribution of the hearing aids on two adult patients diagnosed with auditory neuropathy spectrum (ANS), related to their communication and listening skills. Importance of the problem: Patients diagnosed with the ANS exhibit varied clinical symptoms with predominant complain of difficulty understanding speech, particularly in the presence of noise, and the literature suggests several possibilities of treatment due to these differences. Methodology: We described all audiological, electroacoustic, electrophysiological and imaging tests performed, as well as otorhinolaryngological evaluation. The study included two patients, who have gone through selection and adaptation with the hearing aids and were evaluated after four and fourteen months of continuous use of the device with the application of speech perception test, audiometry in free field with and without the device and they answered to the questionnaires of self-evaluation validated (International Outcame Inventory for Hearing Aids - IOI-HA e Hearing Handicap Inventory for Adults - HHIA). Description os cases: On the audiological assessment, both patients had average audiometric thresholds within normal limits, however for case 1 we observed downgraded thresholds from the frequency of 3 kHz and for case 2 were downgraded thresholds of 250 and 500 Hz; logoaudiometry with inconsistent results with audiometry; normal tympanometric curves and impairment in acoustic reflexes bilaterally; presence of otoacustic emissions bilaterally; absence of auditory brainstem evoked potentials and presence of cochlear microphonic bilaterally; and normal image tests. Both patients received binaural adaptation with hearing aids behind the ear digital, properly regulated based on the audiological features and on the answers given on the process of testing the device. On the assessments was noted that both patients had the threshold improved on free field audiometry with the hearing aids on frequencies downgraded on audiometry, speech perception test with 12% of difference with and without de device and on IOI-HA questionnaire they had an average of 24,6 points (35 total points), on HHIA questionnaire they had an average of 53,6 points (100 total points). With these results, therapeutic intervention was performed with the aim of working the listening and language skills of the patients, who responded rightly to the proposal and showed improvement in speech recognition. Comment: There is still no consensus on the best treatment for ANS. The use of hearing aids have been one of the options for adults, and on this case, we chose to start the intervention with the use of hearing aids and speech therapy for both patients. For the two patients, once adults and with acquired hearing loss, we used as rehabilitative remedy the hearing aids and after the therapeutic intervention, since no satisfactory results were obtained, they were referred for speech terapy (formal auditory training). Conclusions: We conclude that, in the cases described, the use of the hearing aids as a method of rehabilitation, provided benefit observed on free field audiometry, speech perception tests and on self-evaluation of the user, and the therapy was fundamental in improving speech understanding and communication of patients.