### 18.3 Tree intonation ¶

This module is more flexible. Two different CART trees can be used to predict ‘accents’ and ‘endtones’. Although at present this module is used for an implementation of the ToBI intonation labelling system it could be used for many different types of intonation system.

The target module for this method uses a Linear Regression model to predict start mid-vowel and end targets for each syllable using arbitrarily specified features. This follows the work described in black96. The LR models are held as as described below See Linear regression. Three models are used in the variables `f0_lr_start`, `f0_lr_mid` and `f0_lr_end`.