Exaggerated pitch contours and spelling alphabets both raise speech intelligibility in noise.

Evidence

Another possibility is to “chant” the message, which gives an exaggerated pitch contour that assists intelligibility. As a last resort one can use the international radiotelephony-spelling alphabet (Oscar, Bravo, Charlie …) to facilitate communication. — David Howard, Jamie Angus, coustics and Psychoacoustics, 2481

Categorization

• CANDY: The ‘chant the announcement’ trick and the Oscar-Bravo-Charlie alphabet are elevator-conversation gold for anyone who’s strained to hear a train announcement.