The music volume ceiling and the prompt volume ceiling

The prompt volume ceiling and the music volume ceiling system variables are defined so that the maximum permissible volume on your telephone system is not exceeded when a voice sample is played at both volumes and both voice streams are mixed together. When one volume is high, the other must be low, as shown in Table 1

Table 1. Music volume and prompt volume ceilings
Music Volume Ceiling	Prompt Volume Ceiling	Prompt Volume Ceiling	Music Volume Ceiling
0	10 or higher	0	10 or higher
1	5 or higher	1	5 or higher
2	3 or higher	2	3 or higher
3	3 or higher	3	3 or higher
4	2 or higher	4	2 or higher
5	2 or higher	5	2 or higher
6	1 or higher	6	1 or higher
7	1 or higher	7	1 or higher
8 or higher	0	8 or higher	0

Figure 1 shows a diagrammatic version of events in the Musical_Welcome state table; shaded areas indicate when prompts or background music is playing.

Figure 1. Musical welcome state table: volume levels

This graphic is a bar chart in which time is on the x axis and volume on the y. The two kinds of bars represent music volume and prompt volume. Apart from the music fade-in and fade-out heard by the caller, the music is played throughout at its music volume ceiling (SV224). When voice is played, as prompts, the music continues but the prompts are seen to play louder than the music and to be at the prompt volume ceiling (SV223), although below the maximum permissible volume.

Figure 2 shows how you would set the prompt volume ceiling and the music volume ceiling to the same level to play both prompts and tunes at the same volume.

Figure 2. Playing prompts and tunes at the same volume
This graphic is a bar chart in which time is on the x axis and volume on the y. The two kinds of bars represent music volume and prompt volume. The two prompt volume ceilings (SV223 and SV224) are made to coincide so that all sounds are at the same volume.

This graphic is a bar chart in which time is on the x axis and volume on the y. The two kinds of bars represent music volume and prompt volume. The two prompt volume ceilings (SV223 and SV224) are made to coincide so that all sounds are at the same volume.