By Graham K. Rogers

There have been some changes to Accessibility Preferences in macOS, High Sierra (10.13) which provide settings aimed at assisting the disabled. The most obvious change is with the removal of the Dwell sub-section for head- and eye-tracking, and some reorganisation. Dwell functions have been incorporated into the Keyboard section.

In the current version of Accessibility there are five areas of assistance: General, Vision, Media, Hearing and Interacting. The functions are displayed in a window to the left. There are 13 items.

• General: General

• Vision: VoiceOver, Zoom, Display and Speech.

• Media: Descriptions and Captions.

• Hearing: Audio (TTY which was new in Sierra is not shown).

• Interacting: Dictation, Siri (new in Accessibility), Keyboard, Mouse & Trackpad, and Switch Control

As each item in the left side window is highlighted, so controls are shown in the main panel. At the bottom of every pane is a single checkbox: Show Accessibility status in menu bar.

With the number of items in Accessibility, I have split this into three sections. Part 1 covers General and Vision. Part 2 examines Media, and Hearing, while Part 3 (here) covers the more complex Interacting using Dictation, Siri, Keyboard, Mouse, and Switch Control panels.

Interacting

Dictation is a simple panel that controls the input of commands to control computer actions. It works in tandem with the Dictation panel now in the Keyboard preferences panel (previously in Dictation & Speech). If Dictation is turned Off in Dictation Preferences, all options here are greyed out. A button giving access to Dictation Preferences is available when this is Off, but is not displayed when the feature is active.

After an outline description of the purpose, there is a button marked Dictation Commands.

A list of possible verbal commands is shown when the button is pressed. Users may also add their own. Languages are available, depending on the specific installation (mine has United Kingdom English, US English and Thai).

A dictation keyword is available when a box is checked below the Dictation Commands section. The default word to begin dictation is "Computer" but this can be changed. When the box is checked, a microphone icon appears in the menubar and this will display a menu when clicked:

• Listen without requiring Keyword Phrase (a microphone panel appears and dictation can take place - the user presses Done when finished);
• Show Dictation Commands (a panel with available options is shown onscreen); and
• Open Dictation Preferences (this opens the Dictation panel in System Preferences >Keyboard).

Siri Preferences panel

Siri is a new section in the Accessibility section and works with the Siri preferences, although here the focus is on use of the feature for those with speaking difficulties. A single checkbox is shown to Enable Type to Siri. Above this there is a description of the feature which does not over-ride the voice input from a headset. The input is from a keyboard rather than spoken.

Siri option in Accessibility Preferences

Keyboard preferences has seen significant change with the addition of an Accessibility Keyboard pane to the original panel which has been renamed Hardware. Accessibility Keyboard controls appear similar to some of those that were in the previous Dwell Control.

Hardware
The features in this pane were available in previous versions of Accessibility as Keyboard settings. As before, this allows the keyboard to be adjusted so that those with certain difficulties can type with a little less difficulty. There are two checkboxes in this panel: Enable Sticky Keys; and Enable Slow Keys. If a person is restricted to using a computer with one finger only, typing is a problem. Key combinations compound the difficulties. Even typing a capital letter is a problem. With "Sticky Keys" and "Slow Keys", the Keyboard panel provides some solutions to those with limb-movement problems.

With Sticky keys the last-selected modifier key - those used in combinations, like Command or Control - remains active. When turned on (or when a modifier key is pressed) the computer makes a sound. Another sound is made when the feature is turned off. Pressing the key a second time, highlights it (with an optional sound), and pressing a third time cancels the key.

A button marked Options reveals a panel that allows some fine tuning: checking a box allows this feature to be active (or switched off) by pressing the shift key five times. When this is used, a panel appears onscreen to show that the feature is On. A similar panel appears when the shift key is pressed five times to turn the feature Off.

A second checkbox marked "Beep when a modifier key is set" is slightly misleading: the sound is more like a mechanical "clunk". A third checkbox allows display of keys. The placement of the icon that appears may be selected with options for top, bottom, left or right of the screen. If this option is selected in that panel, sticky keys will activate even when the option on the main pane is unchecked: pressing the Shift key five times enters the checkmark in the box.

Slow Keys adds a delay for those who have difficulties with initial or repeated keystrokes. Rather than simply tapping a modifier (or other) key as in touch typing, the key needs to be held down. There is a short mechanical sound when the key is pressed and another when it appears on the screen.

An Options button reveals a slider allowing the acceptance delay to be adjusted, so those with disabilities that make typing very slow can be accommodated. Simply pressing the key one time will produce a sound, but no effect. Depending on the position of the slider, a key needs to be held for a moment before anything will appear on the screen.

To access more features, there is a button here that opens the Keyboard preferences where full keyboard access and key repeat delays can be set or turned off.

Accessibility Keyboard
The information at the top of this new panel shows that this feature lets users type and interact without using a hardware keyboard. It appears to be almost identical to Dwell Control introduced in Sierra.

When this is in use a keyboard appears on screen and this can be used to type in characters. There is also predictive text: suggestions for words. Below the predictive entries are controls for hardware and software features (brightness/dim, volume) and Function keys when the Fn key is pressed. Above the suggestions on the left are an X to close the panel; a minimize control; and to the right a settings icon to control other features (Zoom, Transparency, Dwell actions, Customize, and Preferences).

The feature is controlled by three checkboxes:

• Enable Accessibility Keyboard
  A button for Panel Editor (Customizing) is available and is explained below;

• Fade panel after inactivity -
  A default time of 15.00 seconds may be adjusted up or down from 0.25 up to 60.00 seconds (in increments of 0.25). The time display is live only when the box for this feature is checked.
  The fade feature can also be adjusted from 10% up to 100% so that it can still be seen on screen.

• Play key sounds

Below the three checkboxes is a button that controls when keys are entered. Options are: Mouse down, or Mouse up. With a trackpad this was not necessary.

Two other buttons are available near the bottom of the pane:

Hot Corners are specific to this Accessibility feature and are not related to Hot Corners in Desktop & Screen Saver preferences. Those available here are: Hide/Show Home Panel, Toggle Dwell Pause, Left Click, Right Click, Drag and Drop, Scroll Menu, Options Menu. These are only available when the Accessibility Keyboard is turned on.

Dwell Options are used by eye-tracking technology. Holding the pointer still for a specified time triggers an action. Those available are: Show dwell actions in panels; Show dwell actions in menu bar; Always dwell in panels; Zoom after (a box allows the number of seconds to be adjusted); Hide dwell time indicators; Dwell action (Pause Dwell, Left Click, Double Click, Right Click, Drag and Drop; Scroll Menu, Options Menu); Auto revert to left click; Default time (adjustable, 0.25 - 8.00 seconds); Panel dwell time (adjustable, 0.25 - 8.00 seconds); Dwell movement tolerance (adjustable, 0 - 95 pixels).

A Panel Editor is avalable for customization of keyboards or creation of other panels that might be useful. Panels or existing keyboards can be edited to add buttons that control actions. The editing panel is fairly comprehensive and several types of panel may be edited.

Panels that can be added are Empty, Home - Dwell, Keyboards (ANSI, Alphabetical, ISO, JIS, Numeric), Typing Suggestions. Adding a panel adds it to a list accessible through the Custom button on the ANSI keyboard (to the right of Volume Up/F12). Returning to the ANSI keyboard from a custom keyboard is effected by pressing a Home icon.

Buttons may be added or customized (color, text) to provide additional actions, such as Go back, Open Panel, Dwell, AppleScript, Enter Text, Presss Keys, Open App, System Event, Typing Suggestions. I was able to add a button to an Alphabetical keyboard that opened an application, but could not do this with the standard (ANSI) keyboard.

When customizing, it may be necessary to turn off the Accessibility Keyboard and then re-activate to make any changes active.

Mouse & Trackpad displays a panel that is in two parts, separated by a thin line. At the top is a checkbox marked Enable Mouse Keys. When this is active, the cursor can be controlled using the number pad on the keyboard.

On a notebook computer where there is no number pad, upward (and diagonal) movements are controlled by 7, 8 and 9 keys; U and O control left and right movements; J, K and L control downward (and diagonal down) movements and the letter "i" highlights a paragraph (or line). However, when the Mouse Keys feature is used, the normal typing functions of the keyboard are not accessible: not all keys will type characters on the screen.

As it is not convenient to keep turning this feature on and off to resume typing, an Options panel allows a checkbox to be used to toggle the feature by pressing the Option key five times. a second checkbox allows the trackpad to be disabled when this feature is used.

Also in the Options panel, a slider (Short - Long) adjusts the initial delay of input; while a second slider below adjusts the speed of the cursor movement (Slow - Fast).

In the main panel, below the line, a slider allows adjustment of the Double-click speed (Slow - Fast). Just below, the checkbox marked Spring-loading delay (with its Short-Long slider) is useful when moving files in Finder. Holding a file (or files) over a sub-folder will show the contents of the folder, including any embedded folders which will also behave in the same way if the cursor hovers over them. Also in the this panel is a checkbox marked, "Ignore built-in trackpad when mouse or wireless trackpad is present".

Two buttons at the bottom of the panel give access to Trackpad Options (scrolling speed, scrolling and dragging), and Mouse Options (Scrolling Speed). Trackpad Options is not available on a computer without a trackpad.

Switch Control was new with Mavericks. It is a highly tunable feature that allows connected devices and the Mac to be set up with specific controls or options, for use by physically challenged users. The General pane explains that with this, the computer may be controlled by one or more switches, such as mouse, keyboard, gamepad buttons, or dedicated services.

There is a basic Knowledge base document - HD202865 for Macs, which has an explanation of how these features may be used. A more technical description for Switch Control in Sierra is available in Knowledge Base Document PH25778. There is also information about how Switch Control can be set up on iOS devices (HT201370). [As these are older references (I have only found those updated for Sierra) I would be grateful if anyone has more recent links.]

There are three sections to the Switch Control panel: General, Switches and Navigation:

General is a simple panel with two checkboxes: Enable Switch Control; and Hide panel after inactivity, which has a box for entering a time (default 15 secs). A button marked Panel Editor enables a user to add a new device or switch to the system and operate it with specific applications. A developer may add functions to any of the devices or add new devices to accessibility control. Care needs to be taken when attempting to use such features. The panel is almost identical to the Panel Editor in the Accessibility Keyboard panel (above).

When Switch Control is made active, a panel appears on the screen with a number of controls available: Keyboard, Pointer, App, Dock, Menubar, System, Custom and Location. Pressing any one of them allows a user to control the actions of these input methods. For example:

When the Switch Control pane is displayed, pressing the Space Bar cycles through the options. When the function needed (e.g. Dock) is reached, pressing space bar again selects that. When the space bar is pressed once more, the feature cycles through the item selected (and subsequently down through menus and sub-menus) announcing each item when sound is on.

In the case of the Dock, items are the apps displayed in the Dock. With "App", the system cycles through items in the current application selected, so each feature is announced to the user. When the Keyboard is selected a keyboard pane appears onscreen and the system cycles first through lines of keys, groups (when the space bar is pressed) and then individual keys. Those selected panels also have a Home icon which can be used - when the feature cycles through this - to return to the main Switch Control.

Switches are the commands that a user can use to operate Switch Control. The default is a Space Input, which scans between the controls automatically when Switch Control is enabled (a checkbox allows autoscanning to be resumed). A user may reassign the switch or add others using controls beneath the panel. There are also options marked "Required" and "Optional". A checkbox for Auto scanning at the bottom of the panel can be turned off if a Move to Next Action First control is added. With device scanning the user may also select Timing using a button at the bottom of this panel.

Navigation displays a series of buttons that allow fine-tuning of the way scanning operates when navigating the screen. Operation controls available are:

• While navigating (Do nothing, Speak selection, Play sounds, Speak & play sounds)
• Restart position (After cursor, From start of group, From the top)
• Auto scanning after select (Do nothing, Resume)
• When pointer reaches edge (Do nothing, Bounce back)
• Switch Control cursor size (Small, Medium, Large)
• Pointer precision (Low, High)
• Loops (number of times an action is carried out, 1-10)

See also:

The Wednesday File (26): Accessibility Preferences in macOS High Sierra (2) - Media, and Hearing

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs. He is now continuing that in the Bangkok Post supplement, Life. He can be followed on Twitter (@extensions_th)