Nudging Headphones

Headphones that gently push or pull your head in a direction, opening a third channel to the user that is neither visual nor auditory.

Company: HARMAN International
Year: 2014 — 2016
Role: Concept, prototype program and patenting across three actuation methods
Team: Future Experience Team
Location: Palo Alto, CA

Technology

Center-of-gravity shifting (mechanical / pneumatic)
Asymmetric linear acceleration
Ducted fans and MEMS propulsion
Vestibular perception
Rapid physical prototyping

01The opportunity

Wearables talk to us through screens, sounds and vibration. For navigation, directional warnings and immersive experiences, all three are either occupied or too crude. We asked whether a device on the head could create the sensation of being pushed or pulled in a direction, subtle enough to feel almost subconscious.

02The idea

Ungrounded force feedback on the head. A small imbalance or a brief directional force is perceived through the vestibular system and prompts the user to turn toward it, without a visual or auditory signal. Applications: pedestrian navigation, directional alerts to danger or points of interest, virtual assistants that direct attention quietly, gaming and AR/VR/XR. Suitable for headphones, hearables and head-mounted devices.

03My role

I drove the concept and the prototype program and worked on the patents for all three methods. Because these sensations are almost impossible to describe or simulate, we built the prototypes quickly and exaggerated them for clarity, so the effect could be experienced directly and then miniaturized.

04How it worked

We developed and tested three distinct methods for creating the sensation.

Dynamic weight shifting: Mechanically or pneumatically moving the center of gravity, by redistributing fluid between small containers or moving weights along rails or hinges. Straightforward, effective and suitable for productization.
Linear asymmetric acceleration: Small masses on parallel rails accelerate sharply in the desired direction and return slowly, below perception thresholds. Multiple masses run out of phase so the user feels a continuous push or pull in one direction, without vibration or intermittent poking. Extraordinary sensation, complex mechanics.
Miniaturized air propulsion: Ducted fans, micro turbines, MEMS propulsion or compressed-air micro jets create airflow that nudges the head. Designs include panning fans, thrust-vectoring vanes, and a quadcopter-like assembly with four degrees of freedom. The patent also covers thermal and noise management, including active noise cancellation for the fans.

05Prototype / product

Multiple early prototypes of head-mounted ungrounded force actuators — Fig. 01PrototypeEarly exploration prototypes, one per method. Built fast because the perception of these forces is hard to imagine and immediately clear once felt.

Illustration of the center-of-gravity shifting method for headphones and headsets — Fig. 02ConceptMethod one: shifting the center of gravity by moving fluid or weights. The imbalance is perceived through the inner ear and prompts a head turn. Prototypes are exaggerated; a product would hide miniaturized actuators.

Fig. 03ConceptMethod two: asymmetric linear acceleration. Strong, brief acceleration in one direction and slow return below perception; multiple masses phased to produce a continuous push. Shown here on one axis; extendable to 2D and 3D.

Illustrations and patent figures of fan and jet propulsion methods for nudging headphones — Fig. 04ConceptMethod three: air propulsion. Top: ducted-fan prototypes on headgear, oversized for clarity. Bottom left: patent figures of fan assemblies and thrust vectoring. Bottom middle: a quadcopter-like unit with four degrees of freedom. Bottom right: propulsion on shoulders, wrists or belts.

06Outcome

All three methods were patented. Two patents were granted, the fan-driven force device and the pseudo force device, and the center-of-gravity shifting device was granted in Europe. The underlying perceptual principles are documented in the scientific literature referenced in the patents.

Three actuation methods prototyped
Three patent families

07Patents, press, links

Patents

US 9984540 B2Fan-driven force device2018
US 10296018 B2Pseudo force device2019
EP 3254121 B1Center of gravity shifting force device2019