How is a "hearing aid" defined according to the applicable statute?

The definition of "hearing aid" as a device designed to improve hearing encompasses a broader spectrum of functions than merely amplifying sound. While amplification is a critical aspect of hearing aids, the term “improve hearing” indicates that these devices may address various hearing-related issues beyond just making sounds louder. This can include modifying sound quality, filtering background noise, or using technology to help the user better perceive certain frequencies.

The other options are more limited in scope. For instance, defining a hearing aid solely as a device that amplifies sound does not capture its complete functionality and purpose. Focusing exclusively on digital listening or sound isolation also misses the multiple technological advancements and designs that contribute to hearing improvement, such as analog devices or those that provide directional sound. Thus, the choice that aligns with the comprehensive intent and purpose of hearing aids as outlined in the statute is the one describing them as devices designed to improve hearing.