Vowels are also distinguished in terms of how and where each sound is produced, but they involve fewer parts of the overall vocal apparatus. The International Phonetic Alphabet is useful as a tool to describe the speech sounds of any human language. The IPA symbols provide a fairly accurate representation of speech if properly used. Although the writing systems of languages may vary, a transcription of the speech sounds in IPA will be understandable by any linguist who knows the system. It is also important to recognize the difference between phonetic transcription and orthography.
Phonetic writing is helpful because orthographic writing is often ambiguous or unclear.
There is also an Americanist tradition in phonetics that has slightly different symbols for certain speech sounds. Length Length is a phonetic feature that affects vowels and consonants within a syllable. In Finnish there are long and short vowels and consonants. Intonation Intonation is a phonetic feature involving changes of pitch over a phrase or sentence. Intonation normally adds emotional rather than lexical meaning.