---
name: Sonification
slug: sonification
category: accessibility
status: published
created: 2026-08-21T00:00:00.000Z
modified: 2026-08-21T00:00:00.000Z
definition: Turning data into sound, mapping a series to pitch or rhythm, so a
  chart can be heard as a shape rather than described one value at a time.
aliases:
  - name: data sonification
    source: community
  - name: audio chart
    source: community
  - name: audio graph
    source: community
  - name: data table alternative
    source: community
tags:
  - dataviz
  - sound
relations:
  contrastWith:
    - chart-description
    - earcon
  variantOf: []
  partOf: []
  seeAlso:
    - chart
implementations: []
sources:
  - title: "University of Washington: Making data visualizations accessible"
    url: https://www.washington.edu/accesstech/dataviz/
  - title: "Wikipedia: Data sonification"
    url: https://en.wikipedia.org/wiki/Data_sonification
demo: inline
exhibit: false
useWhen: a chart has to be perceivable without sight
---

A sonified chart plays the series instead of describing it: each value becomes a tone, usually with
pitch carrying the value and time carrying the axis, so twelve months of revenue take about three
seconds to hear. What that conveys is shape. A steady climb sounds like a climb, a spike sounds like
a spike, a plateau sounds like nothing changing, and a reader who has heard the sweep once knows
where in the series to ask a question. It is the same trick a heart monitor plays, and it works for
the same reason: hearing is very good at change over time.

What it conveys badly is values. Pitch discrimination is coarse, absolute pitch is rare, and nobody
listens to a tone and reports 41.8 percent. This is why sonification is an addition rather than a
replacement. The reader who wants the number needs a [data table](/data-table) or a
[long description](/long-description); the reader who wants to know whether the line went up needs
three seconds of audio rather than a paragraph read out one figure at a time. Serve both, from the
same data, and let the reader pick.

Design decisions that matter more than the synthesis. Map value to pitch rather than to volume,
because loudness is heard as importance and a small value should not sound like a mistake. Keep the
mapping monotonic, so higher is always higher, and say what the mapping is before the sweep plays,
in the same way a visual chart labels its axis. Mark the axis audibly if the series is long, with a
click per month or a change of timbre per quarter, since a reader cannot count fifty tones any more
than they can count fifty gridlines. Give a play control with a real
[accessible name](/accessible-name), let the reader replay and step point by point, and never start
the audio by itself: unrequested sound is exactly what [audio control](/audio-control) exists to
undo.

The vocabulary is still settling. Audio chart and audio graph usually mean a chart component with
sonification built in, sonification means the technique in general, and the phrase data table
alternative describes the role it plays rather than the sound it makes. Whichever word you use, the
[alt text](/alt-text) rule underneath does not change: the chart still needs a short text
equivalent, because a reader browsing a page of figures is not going to play all of them.