The measurement module ACALES (Adaptive CAtegorical Listening Effort Scaling) is a measurement method for hearing care professionals and audiologists to measure the subjective listening effort. The ACALES method makes it possible to measure the mental 'listening load' or listening effort, a person must expend to understand speech in noise.
This is an additional additional dimension to speech intelligibility. When measuring subjective listening effort, the patient/client rates the patient/client rates how strenuous it is to follow a speech in noise on a 13-point scale from "effortless" to "extremely strenuous". The result diagrams show the subjective listening effort as a function of the signal-to-noise ratio. This way you may compare different hearing systems or fittings of hearing systems, or investigate different spatial listening situations.