What is data sonification?

An introduction to data sonification, the practice of turning data into sound.

Simply put, data sonification is the practice of taking data and representing it in the form of sound. Just as data visualization uses shapes, color, size, and composition to represent data visually, data sonification uses volume, pitch, timbre, rhythm, duration, and more to represent data sonically.

There are plenty of examples from our daily lives where information is conveyed through audio: ○ Nagging beep of a credit card chip reader — "remove your card!" ○ Wailing alarm from a smoke detector — "smoke!" ○ Booming clang of a bell tower on the hour — "it's 4 o'clock!"

Sonification takes this idea further. It allows us to hear patterns in complex data, and consume information in a new and interesting way.

Not yet imagining what this can sound like? Here are some examples right off the bat:

The New York Times: "Nine Rounds a Second: How the Las Vegas Gunman Outfitted a Rifle to Fire Faster"

NPR's Planet Money: "U.S. Home Prices, Sung As Opera"

Marketplace: "What sound does a volatile stock market make?"

Looking for another way to put it? Check out this great explanation of data sonification from researcher Jordan Wirfs-Brock. Or, consider a general definition of data sonification included in the summary of the Sonification Handbook (2011) website.

Approaches to sonification:

The most common types of data sonification are parameter mapping and audification. These approaches are further elaborated in the Methods section, but briefly put:

• Parameter mapping matches values in a data set to different dimensions of audio.

• Audification takes data which in original form is not audible to the human ear, and manipulates it so that it can be heard.

Data visualization and sonification can combine to create audio-visual representations of data. You can make a chart audible, like in this audiochart of the Global Living Planet Index.

There are several data sonification methods and tools you can use to sonify data. You might use an algorithmic tool to generate sounds from your data set, or you might manually compose audio to reflect data (what is called “punk” sonification). You might use a combination of computer-based methods and hands-on methods. You might even perform a sonification in person. There are many possibilities for creativity in sonification, and opportunities for capturing the attention of listeners with data-driven sound.

Auditory display, the larger category:

Sonification is part of a bigger category called auditory display, which is the communication of information through audio. This is often in the context of interactive interfaces, appliances, or devices. Examples include the radio display inside a car, voice assistant technologies, the tune that a washing machine sings when it’s done washing clothes, and so on. Data sonification is a subset of auditory display which refers specifically to communicating data through sound.