Cochlear Implants
Introduction
Compression
See Dynamic_range_compression on wikipedia.
Terminology of Critical Points in the Mapping Function
In scientific literature, three key levels are recognized: 1. hearing threshold, 2. comfortable level, and 3. pain threshold, each denoted in various ways.
The following abbreviations are commonly used to describe specific levels of electrical stimulation:
- T, THR, or THL: These stand for Threshold Level, or Threshold Hearing Level. This is the lowest level of electrical stimulation that the user can perceive.
- M, MCL, or C: These abbreviations stand for Most Comfortable Level, Maximum Comfortable Level, or Comfortable Level. This level refers to the point at which sounds are comfortably perceived—neither too loud nor too soft.
- USL, MSL, UCL, or LDL: These stand for Upper Stimulus Level, Maximum Stimulation Level, Uncomfortable Loudness Level, or Loudness Discomfort Level. This level indicates the point at which sound becomes painful or uncomfortable for the user.
The terminology can vary depending on the manufacturer. For example, for the comfort level in clinical software:
- Advanced Bionics uses 'M-level',
- Cochlear uses 'C-level',
- Med-El uses 'MCL'.
There can also be some variation in the precise definitions of these terms.
The term "Maximum Comfortable Level" is less commonly used and can sometimes refer to the highest level that is still comfortable, just below the pain threshold. This usage can be confusing and should be avoided where possible.