ITU-T RECOMMENDATION E.183 – Guiding principles for telephone announcements
1 Introduction
2 Content of announcements
3 Timing of announcements
4 Speech quality
5 Tones after announcements
6 Concatenated-word announcements
    6.1 Fluency problems
    6.2 Intonation problems
    6.3 Presentation of numerical information
    6.4 Update problems
7 Tones and announcements for use in telephone services
8 Preferred listening levels for announcements