| Tone number | Description | Pitch levels | Symbol | Example | Gloss |
|---|---|---|---|---|---|
| 1 | high level | 55 |  | ma | mother |
| 2 | high rising | 35 |  | ma | hemp |
| 3 | low falling rising | 214 |  | ma | horse |
| 4 | high falling | 51 |  | ma | scold |
Many African languages have a two-tone system, and the tone bearing unit (TBU) is often the syllable nucleus. This means that every syllable has an associated tone which is either high (/bá/) or low (/bà/). If there are three tones, high, mid and low, the mid tone may be marked with a horizontal line over the vowel (my browser won't do this) or it may be unmarked. The following examples are from the Nupe language Nigeria) which has three tones. Vowels without an accent are mid tones:
| ebà | place | eba | penis | ebá | husband |
| edú | kind of fish | èdù | Niger river | èdu | kind of yam |
| edu | thigh | edù | deer |
Languages change all the time, and it is well documented that some tonal languages have changed into non-tonal languages. Such languages generally develop a stress system. Swahili is one such language. Korean is in the process of transition, and at the present some dialect of Korean are tonal and others (such as Seoul Korean) are not.
Simple high, mid and low tones are called level tones, because they do not exhibit pitch variation within one TBU. Mandarin Chinese has a rather different tone system in which pitch may move in the course of a TBU. These tones are called contour tones. In Mandarin, there are four tones, and they are usually described with reference to a 5 point scale where 1 is the lowest and 5 the highest pitch. The four tones are listed below (examples are from Ladefoged, p. 255):
| Tone number | Description | Pitch levels | Symbol | Example | Gloss |
|---|---|---|---|---|---|
| 1 | high level | 55 | | ma | mother |
| 2 | high rising | 35 | | ma | hemp |
| 3 | low falling rising | 214 | | ma | horse |
| 4 | high falling | 51 | | ma | scold |
Phoneticians and phonologists who work within a single language family, such as Bantu languages of Africa, or Chinese and related languages, may use numbers to refer to these tones, which simplifies transcription. Obviously, any such transcription must be explicit about what the numbers refer to.
When several tones are produced in succession, they will influence
each other, and the result may be somewhat simplified. Predictable
interactions among tones are called tone sandhi
phenomena. Ladefoged gives the example of Shanghai Chinese, where the
word for symphony /
.
.
/ has
three syllables whose underlying tones are 51-35-5. These surface as
the sequence 5-3-1 (p. 256).
Tone languages also exhibit intonation, in ways not unlike English, so that the resulting tonal variation can be quite complex.