This exercise is one of the exercises you can use to practise
  intervals.  The concept is pretty simple: You press the New
  interval button to play a random interval, and then you
  should tell what interval it was.  
- 
        New interval:
        Alt-n
    
- 
        Repeat:
        Alt-r
    
- 
        Repeat melodic:
        Alt-m
    
- 
        Give up:
        Alt-g
    
Table 2.1. Keys used to identify interval
| Minor second: 1 | Perfect fourth: 2 | Major sixth: 3 | Minor ninth: 4 | 
| Major second: q | Diminished fifth: w | Minor seventh: e | Major ninth: r | 
| Minor third: a | Perfect fifth: s | Major seventh: d | Minor decim: f | 
| Major third: z | Minor sixth: x | Perfect octave: c | Major decim: v |