Class 2 ( hi medium only samples)
| length (sec.) | Mel. profile | Dyn. profile | Note 1 | Note 2 | ||
| In mail 4 | 1.36 | 
 | 
 | Sleigh bells | ||
| Feedback yes 5 | 0.37 | 
 | 
 | Piano medium high freqs. +++ | Cartoon | |
| Out mail 4 | 1.90 | 
 | 
 | Ding | ||
| In radio 5 | 0.76 | 
 | 
 | Image : telephone noise | ||
| In radio 3 | 0.55 | 
 | 
 | almost sinus | ||
| Out radio 3 | 0.49 | 
 | 
 | idem | 
-> comments <-
(~source perception) recognizable instruments - metallic percus - bell like - household stuff
(~subjective perception) melodic but too short - beurk - musical effects
(~ feedback degree +1) 'it's ready' - got a response - time's up - got your info
(~ feedback degree 0) hint, something not important to do
*remember typical "feedback degree +1" profile according to sonification study :
| Polyphonic / monophonic | monophonic | 
| Dynamic profile |  | 
| Melodic profile |  | 
| Length | 0.5 to 1 s. | 
and "feedback degree 0" profile :
| Polyphonic / monophonic | both | 
| Dynamic profile |  | 
| Melodic profile |  or  | 
| Length | 0 to 0.5 s | 
-> conclusions <-
This class 2 only contains short, high-spectrum / pitched samples.
This can modify our definition of "feedback degree 0 and +1" categories, which depend more on the spectrum aspect, and less on mel / dyn profiles.
It also means that this 'hi medium only' sound aspect is so important that it makes a class by itself.