Speech

There are two types of tracks available in the Highcharts sonification module: Instrument tracks and Speech tracks. A speech track is a track that plays speech announcements using speech synthesis.

Speech tracks have parameters that can be mapped to, just like instrument tracks, including volume, rate and pitch. For a full list of available options for speech tracks, see defaultSpeechOptions .

Basic Speech Tracks

To define a speech track, set the track type to "speech":

series: [{
    data: [1, 2, 3, 4, 5],
    sonification: {
        tracks: [{
            // This is an instrument track
            instrument: 'flute',
            mapping: {
                volume: 0.8
            }
        }, {
            // This is a speech track
            type: 'speech',
            mapping: {
                volume: 0.4,
                text: 'Hello world'
            }
        }]
    }
}]

Speech Mapping

The text  mapping parameter determines what is being spoken. It can either be a format string  or a function.

The below demo illustrates using a format string to map the speech to announce Y-values. It also maps the speech pitch  to Y-values, meaning the voice speaks at a higher pitch at higher values, and lower at lower values.

Next Steps

Often with speech tracks we don’t want them to play all the time. Next up is looking at conditional tracks , a powerful tool when building sonifications.