Abstract
A mobile device continuously synthesizes an audio voice modulated in real time by its own inertial motion, so that a user physically swinging or carrying the device hears themselves as sound. The same inertial signal that drives the synthesis is simultaneously used as the detection carrier for a periodicity estimator, which locks onto the user's repetitive-motion period (gait cadence, arm swing) by folding N recent cycles per candidate period and scoring inter-cycle coherence. Octave ambiguity — the classic step-versus-stride error — is resolved by folding at twice the candidate period and testing the two resulting half-cycles for asymmetry, exploiting the fact that human gait produces unequal left and right footstrikes. On lock, the system extracts from its buffer a single verbatim measured motion cycle whose length best matches the locked period, and loops that cycle as a percussive template phase-anchored to a predicted downbeat. While the template loops, the system concurrently requests media content having a tempo corresponding to the locked period. The template's loop count is a minimum, not a duration: it continues looping until the media is ready, then terminates on a downbeat boundary and hands off, so network latency is absorbed as additional musically-coherent bars of the user's own rhythm rather than as silence or as an off-beat entry. A separate purity-gated single-axis gesture detector allows the user to re-invoke the instrument mid-activity and renegotiate tempo. Three alternative periodicity estimators are disclosed.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Gulati, Harnek, "Motion-Driven Audio Instrument with Same-Signal Cadence Lock and Beat-Aligned Handoff to Tempo-Matched Media, Using the User's Own Measured Motion Cycle as a Variable-Length Rhythmic Bridge", Technical Disclosure Commons, ()
https://www.tdcommons.org/dpubs_series/11261