Clinical Verification of Hearing Aid Performance

The general goal of providing amplification is to improve functional auditory capacity and restore good communication skills. Amplification should restore the audibility of soft sounds, provide improved intelligibility of speech at conversational listening levels, and ensure that intense sounds are not amplified to an uncomfortably loud level. There are several prescription methods that provide frequency-specific target values for soft, conversational, and intense sounds. Despite differences in the target values, no validated prescription method has been clearly shown to be superior to any of the other methods in terms of patient benefit (e.g., greater satisfaction, less residual disability). However, clinical studies have clearly shown that when a well-researched prescriptive approach is used and appropriate gain is delivered across frequencies, speech intelligibility is enhanced, and there is improved patient benefit and satisfaction. There is also irrefutable evidence that the audiologist can improve the match to the prescription target values using a probe microphone placed within the patient’s ear canal. As a result, carefully conducted verification is an essential component of long-term success with amplification. The most recent generation of prescription methods provides a degree of personalization to the target values beyond that associated with hearing threshold levels. However, there is an urgent clinical need to address the wide range of clinical outcomes that occur in hearing aid users with apparently similar characteristics.