A data source is most efficient when all its symbols are equally probable

Evidence

Notice that, except for the case of all symbols having equal probability, all the other sources have a total source information, or entropy, of less than 3 bits. This is always true: the most efficient information source is one that uses all its possible symbols with equal probabilities. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2633

Categorization

• QUESTION: This claims maximum entropy equals maximum information efficiency — worth wrestling with whether ‘efficiency’ here is about information content rather than audible quality.