ALPHADIGIT CHALLENGES


Confusion Pairs

Minimal articulatory differences between words

E-Set, A-Set, Nasals, ...

e.g. 'B' and 'D' differ in only the first 10-20 msecs.

Problems Specific to Telephone Bandwidth

Lose high frequency content

'S' and 'F' are distinguished by their high frequency patterns

Even hard for humans to recognize