Which of the following measurements is included in electroacoustic analysis?

Electroacoustic analysis is a method used to assess the performance of hearing aids through various measurements that relate directly to auditory signal processing. Harmonic distortion is one of the key measurements in this analysis, as it evaluates the purity of the sound that the hearing aid produces. Specifically, harmonic distortion measures how much unwanted harmonics are present in the output compared to the desired signal, allowing dispensers to assess audio quality and fidelity.

The other options, while related to different aspects of hearing or hearing aids, do not fall under the category of electroacoustic analysis. The type of ear canal concerns anatomical considerations rather than a measurement of the hearing aid's acoustic performance. The patient's hearing history relates to their audiological background rather than real-time electroacoustic performance metrics. Lastly, frequency of earwax buildup is more about physical obstructions that could affect sound transmission and not a direct measure of the hearing aid's electroacoustic characteristics. Thus, harmonic distortion stands out as the relevant measurement for electroacoustic analysis.