Benefits of compression amplification in telephone bluetooth-assistive listening devices for people with hearing loss

Background: Telephone conversation is one of the main scenarios where people with hearing loss require assistive listening devices (ALDs). Such people experience the greatest degree of difficulty during phone conversations in noisy environments. Purpose: This study compared the benefits of a linear scheme with a compression amplification scheme fitted with a prescription for sloping-type hearing loss implemented in a Bluetooth ALD in quiet and noisy environments. Research Design: Word recognition scores (WRSs) for the Mandarin monosyllable recognition test (MMRT) and participants' satisfaction ratings were measured to serve as objective and subjective results, respectively. Study Sample: Twelve native Mandarin speakers aged 27-68 yr with mild to moderate sensorineural hearing loss participated in this study. Intervention: A compression amplification scheme with a prescription in maximizing speech intelligibility for sloping-type hearing loss was implemented in a Bluetooth ALD. Data Collection and Analysis: The MMRT WRSs of participants wearing the Bluetooth ALD were collected. Each test was conducted in a soundproof booth under quiet and 65-dBA speech noise environments. Each participant completed a satisfaction questionnaire administered by an audiologist. The collected WRSs were examined using analyses of variance and the satisfaction ratings were analyzed using Wilcoxon signed rank tests. Results: The mean MMRT WRSs of the compression amplification scheme were significantly higher than those of the linear scheme (57% and 53% higher in quiet and noisy environments, respectively). The mean satisfaction ratings of both schemes were between neutral and satisfied in the quiet environment, whereas in the noisy environment, the participants were more satisfied with the compression scheme than the linear scheme. Conclusions: The results demonstrate the effective benefits of the compression amplification scheme fitted with a prescription in maximizing speech intelligibility for sloping-type hearing loss implemented in a Bluetooth ALD for people with mild to moderate hearing loss.