What is audiofunctions.web?

audiofunctions.web is a web application that shows math function graphs and supports people with visual impairments to explore them. audiofunctions.web works on most browsers on smartphones, tablets, desktops and laptops.

How to run audiofunctions.web

Open a link to audiofunctions.web or visit www.inter-agibile.unito.it/audiofunctions
If you are using audiofunctions.web on a desktop or laptop, we suggest to enlarge the browser window to the entire screen. You can use the window “maximize” button (this may have different names on different systems).
Turn your screenreader off.
Make sure volume is on and, possibly wear headphones
On some devices, you need to reload the page before starting exploring the graph (press CTRL+r). We hope to fix this problem asap.
To start the exploration of the function: if you are using a touchscreen, tap with one finger in the middle of the screen; if you are using a keyboard or a trackpad/mouse, press “s”.

How to explore the graph

You can explore the graph by touching the screen, moving the pointer (with mouse or trackpad) or using the keyboard. While you are exploring, audiofunctions.web produces sounds that help you having a quick idea of the function.

If you explore with the keyboard, use the left-right arrow keys to move along the x axis (a complete list of keyboard commands is reported below). Exploration starts at the center of the graph. While you move left/right, you can hear a sound that depends on the value of f(x) for the x value you are exploring. The higher the value of f(x), the higher the pitch of the sound you will hear. Also, the more you move on the right part of the screen, the more you will hear the sound coming from that direction (same for left). This can be better appreciated by using headphones.

If you explore with the touch or the pointer, when you touch or move the pointer to a point (x, y), the value of the function in x is played. For example, if you touch the point (1, 10) and the function is f(x)=2x, then audiofunctions.web plays a sound that corresponds to the value (1, 2), because for x=1, f(x)=2. So basically, you can slide your finger or move the pointer left and right and listen to sound. There is one additional thing to know: when you touch or move the pointer on the line of the function graph, you will hear the sound at max volume. The farther you move up or down with respect to the function, the lower you will hear the sound.

How to get additional information about the point being explored

While you are exploring a function graph, you can ask audiofunction.web to read further information about a specific point of the function (e.g., the coordinates, the first and the second derivative).

On the touchscreen, while you are exploring by sliding one finger over the screen, you can tap with the second finger to read further details about the point touched with the first finger. As soon as you pick up the second finger, audiofunctions.web stops reading.

On a trackpad/mouse you can read further details about the function by clicking on the touchpad. If you press the right click trackpad/mouse button audiofunctions.web stops reading.

On a keyboard you can read further details by pressing the “Space” key. If you press the “Space” key again, audiofunctions.web stops reading.

Do I really need to wear headphones?

Headphones convey stereo sound in your left and right ears. So you can get advantage out of headphones by listening to the sound direction. For example, if you are exploring on the left of the function graph, the sound will come from the left ear. Vice versa, if you are exploring on the right of the function graph, the sound will come from the right ear. However, you can listen to the sound also without headphones, regardless of its direction.

List of commands

Keyboard

s: start interacting with audiofunctions.web
left/right arrows: explore on the left or on the right
up/down arrow: explore further on the left or further on the right
esc: go back to the origin
space: it starts/stops reading further details (coordinates, first/second derivative)
m: it plays all the function graph

Touchscreen

slide one finger: explore the function graph
tap with the second finger while sliding the first finger: read further details of the point
pick up the second finger while it is reading the details of a point: stop reading the details
double tap with the second finger while exploring: it plays all the function graph

Instructions