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

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

Feel free to search this API through the search bar or the navigation tree in the sidebar.

# sonification.defaultSpeechOptions.mapping.volume.mapTo

A point property to map the mapping parameter to.

A negative sign `-` can be placed before the property name to make mapping inverted.