For many disabled people, touch carries information that others get from a screen or a speaker. A deaf user relies on vibration to know a phone is ringing, a blind user feels the phone confirm each gesture while a screen reader speaks, and a deafblind user may read everything through a refreshable braille display. Good haptic design for these users rests on the same qualities that make haptics good for anyone, signals that are easy to tell apart and easy to adjust, with much less room for error.
Alerts for deaf and hard of hearing users
Vibration is the standard substitute for sound. Phones and watches vibrate for calls and messages, and dedicated alerting devices include vibrating alarm clocks, bed shakers that sit under a pillow or mattress, and signalers that relay a doorbell, a baby monitor, or a smoke alarm to a wearable receiver. Distinct patterns for each source matter more here than on a typical phone, because the user can't hear which event triggered the alert.
Wearables that translate sound into vibration patterns on the wrist or torso have been studied as sensory substitution aids for decades. Results vary by device and by how much training users get, and these aids are best treated as a supplement to hearing aids, cochlear implants, and visual alerts.
Screen readers and phone settings
A flat touchscreen has no physical landmarks, so blind and low-vision users depend on feedback to know a gesture registered. VoiceOver on iOS and TalkBack on Android pair spoken output with sound and vibration cues, and both let users adjust or turn off those cues. Haptic confirmation works best as a companion to speech, marking that something happened while the voice says what happened.
Both platforms also give users control over vibration itself. iOS lets people record custom vibration patterns and assign them to individual contacts, which tells a deaf or deafblind user who's calling without a glance at the screen, and its accessibility settings include a switch that turns vibration off across the system. On many Android devices users can set vibration strength separately for calls, notifications, and touch feedback, and apps can give each notification channel its own pattern.
Braille displays and tactile graphics
Refreshable braille displays raise and lower small pins to form a line of braille cells, and most use piezoelectric reeds to move each pin. Every cell needs several precisely controlled actuators, which keeps these displays expensive and limits most of them to a single line of text. Multi-line and full-page tactile displays that can show graphics and tables exist, but they remain specialized equipment.
Navigation without sight
Several kinds of mobility aid use vibration to report what the user can't see. Electronic canes and handheld devices vibrate when an ultrasonic or optical sensor detects an obstacle, including objects at head height that a standard cane misses. Belts and wristbands with several actuators have been used in research and in some products to indicate direction by where the tap lands, and phone navigation apps can add vibration cues to spoken turn instructions.
The vocabulary in these devices has to stay small and unambiguous, since a misread cue can send someone the wrong way at a crossing. The article on designing a tactile language covers how to build patterns that hold up under distraction, and the wearables guide covers the limits of the wrist as a place to deliver them.
Design rules that carry over
Haptics shouldn't be the only channel for anything critical. Pair it with sound or a visual change so a user who can't feel it, because of a loose watch, gloves, or reduced sensation, still gets the message. Reduced tactile sensitivity is common with age and with conditions such as peripheral neuropathy, so adjustable intensity matters, and so does the option to turn vibration off for people who find it uncomfortable or distracting.
Consistency matters as much as strength. The same pattern should mean the same thing everywhere on a device, and patterns for urgent events should stay reserved for urgent events. ISO 9241-920 gives ergonomic guidance on tactile and haptic interaction that works as a checklist, but no standard replaces testing with the people who'll depend on the device, including blind, deaf, and deafblind users. The guide to measuring haptic quality covers the bench side of that work.