Originally Posted by
marchino61
I find this quite intriguing. What is the source of this information?
The name given is low levels of discrimination. The ability to make out a particular sound or voice in amongst other sounds, or even just the ability to understand speech.
In the extreme people can hear a voice but not actually discriminate the sounds into meaningful words. This is common in the deaf/hard of hearing and audiologists will carry out speech discrimination tests. This is usually done by playing voices of different people at different sound levels with or without background noise. They may talk in snippets or single words so there is no contextual clue to what the word is, or give a sentence that provides some contextual clues to what is being said.
The count the bleeps type hearing test is just for that
hearing it does not identify people who cannot understand voices or sounds well against background noise.
I am surprised that this is not tested for. The person suffering a loss of speech or sound discrimination may not be aware of it, but will find talking/listening in noisy surroundings difficult and tiring.
This is totally different to the 'attentional' or 'cognitive' tunneling effect, where under pressure humans will focus on one particular part of their environment and exclude all others. If that is the wrong thing then that will lead to problems in a cockpit environment.
Sounds are one of the first stimuli to be filtered out, the last to be filtered out are haptics (touch and feeling) hence the reason for stick shakers.