You may see OSPL90 on the manufacturer specification sheet, which refers to the MPO of a hearing aid in the 2-cc coupler. Other terms relating to amplification are the MPO, or maximum power output, which is, of course, the maximum output of the hearing aid. We talk about all this in Part 2 of this series. This is the level right before uncomfortable.Īuthor's Comment: It is debatable whether the output of a hearing aid should set at the LDL itself, or just below it, which would be the ULC (which is more or less #6, "Loud But Okay" on the Cox Contour Test). Something a little different, however, are ULCs, which stands for the upper level of comfort. Regardless of what you call it, LDLs, UCLs, and TDs all refer to the same thing. Others prefer threshold of discomfort (TDs). I know that some of you prefer the term uncomfortable loudness levels (UCLs), but personally, I have never quite figured out what the C stands for because "uncomfortable" is all one word, but it seems to be a popular term. I like to use the term loudness discomfort levels (LDLs), and will use that term throughout this article. But before we dive into this discussion, it might be helpful to review a few terms. How loud is too loud? There are many ways to measure loudness both in the psychoacoustic sense and physically related to the output of a hearing aid. The handout can be downloaded here (PDF). The handout for the recorded course contains several tables and figures that may be helpful for readers of this text course.
![audio decibel convert to linear scale audiometer audio decibel convert to linear scale audiometer](https://i.pinimg.com/originals/d7/09/5c/d7095c2c5649276b5eccf76ef53751cb.png)
To register to view the recorded course, click here. The author, Gus Mueller, added additional comments 5/01/11. Editor's note: This is an edited transcript of the Siemens eLearning Seminar recorded on 7/10/09.