How to write phonemes

If you write down sounds you must ensure that the signs you use can be distinguished from normal letters.

In normal orthography it is not necessary to indicate different sounds. For example, English speakers intuitively know the letter ‘a’ can be pronounced differently in two words; consider the a in star and in bad.

IPA

More than one hundred years ago the International Phonetic Association (or Association Phonétique Internationale), abbreviated as IPA, set up a special symbol set to describe sounds—phonemes—in a written form.

IPA is not only the abbreviation of the organization, it is also the name of the symbol set. The IPA symbols are mainly based on Greek and Latin letters. Most dictionaries published today use the IPA symbol set to represent phonemes.

To learn more about the IPA, visit: https://www.internationalphoneticassociation.org/.

SAMPA

As there are many special characters used in the IPA symbol set, it is not suitable for use with computers. Computer readable dictionaries use alternative symbol sets instead that have been developed especially for this purpose. One of the most commonly used is the SAMPA (Speech Assessment Methods Phonetic Alphabet) symbol set.

The SAMPA set only uses symbols found on most computer keyboards, but aims at similarity to IPA wherever possible. SAMPA exists for almost all European languages.

For information about SAMPA and its history, you can visit the home page of the department of linguistics of University College London: http://www.phon.ucl.ac.uk/.

Nuance Recognizer uses a modified SAMPA symbol set. In some cases these symbols are different from the SAMPA symbols found on the SAMPA site. For better recognition rates Nuance has changed some of the symbols to better support the ongoing process of training the system. For example, two similar sounds are sometimes described with only one SAMPA symbol.