# Welcome to the Highcharts Gantt JS (gantt) Options Reference

These pages outline the chart configuration options, and the methods and properties of Highcharts objects.

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# sonification.defaultSpeechOptions.mapping.text

The text to announce for speech tracks. Can either be a format string or a function.

If it is a function, it should return the format string to announce. The function is called for each audio event, and receives a parameter object with `time`, and potentially `point` and `value` properties depending on the track. `point` is available if the audio event is related to a data point. `value` is available if the track is used as a context track, and `valueInterval` is used.

If it is a format string, in addition to normal string content, format values can be accessed using bracket notation. For example `"Value is {point.y}%"`.

`time`, `point` and `value` are available to the format strings similarly to with functions. Nested properties can be accessed with dot notation, for example `"Density: {point.options.custom.density}"`