Not all touchscreen devices are powered by capacitive or resistive touch-sensing technology. If you keep up with our blog here at Nelson-Miller, you’re probably well aware that these are the two most common types of touch-sensing technology used in smartphones, tablet computers, monitors, human machine interfaces (HMIs) and other touchscreen devices. In recent years, though, several new technologies have emerged, including acoustic pulse recognition. So, what is acoustic pulse recognition, and how does it work exactly?

Overview of Acoustic Pulse Recognition

Acoustic pulse recognition is an alternative form of touchscreen technology that relies on acoustic waves to identify the user’s touch commands. When you touch the surface of an acoustic pulse recognition device, it creates an acoustic wave — also known as a sound wave — within the substrate layer that’s measured by several transducers. The transducers are installed around the edges of the device, and their primary purpose is to measure any acoustic waves created by the user.

Upon reading this, you might be wondering how acoustic pulse recognition devices are able to identify touch commands without picking up on ambient noise in the surrounding environment. After all, touchscreen devices are rarely used in a dead-silent environment. And if there’s ambient noise present, you may assume that an acoustic pulse recognition device will identify this noise as a user’s command. Well, acoustic pulse recognition devices create a stored profile of the sound created by a user’s touch. When the device “hears” something via its transducers, it cross references the sound with the stored sound profile. Assuming the two match, it responds with the appropriate command. If the two sounds don’t match, it ignores the sound, believing that it’s simply ambient noise and not an actual touch command.

Benefits of Acoustic Pulse Recognition

Acoustic pulse recognition isn’t as popular as resistive or capacitive touchscreen technology. Nonetheless, it offers several noteworthy benefits. For starters, acoustic pulse recognition devices can be used with a bare finger, gloved finger or stylus. This is a huge benefit that allows for increased utility, as capacitive touchscreen devices can only be used with a bare finger or special capacitive stylus.

Second, acoustic pulse recognition devices are highly responsive. Even a light-pressure touch will register a touch command. And because of their high sensitivity, acoustic pulse recognition devices last a very long time. The minimal pressure placed against their surface reduces wear and tear that would otherwise degrade the device.