jitter: one construct, many systems

In voice science, jitter is the cycle-to-cycle variation in the duration of successive glottal periods during sustained phonation, small, involuntary fluctuations in how long each vibration of the vocal folds lasts. Titze's Principles of voice production defines it as a perturbation measure of vocal stability, where higher jitter signals a rougher, less periodic voice. The referent is the irregularity of a nominally periodic biological oscillation, the same construct as clock jitter and packet jitter, here realized in the larynx and measured in microseconds or as a percentage of the mean period.[1]

Unit

The cycle-to-cycle variation of the glottal period, in microseconds or percent

Recovery means

Not applicable

Measured by

Measured as period perturbation (absolute jitter or jitter percent) over sustained phonation

In networking, jitter is the variation in the delay of packets in a stream (the degree to which arrivals that were sent at even intervals turn up unevenly), which degrades real-time audio and video until a playout buffer smooths it out. Kurose and Ross's Computer networking treats packet delay variation as a key quality-of-service metric for interactive media. The referent is the variability in the timing of a stream of events, the same construct as a wobbling clock or an unsteady voice, here measured as the spread of inter-arrival delays.[2]

Unit

The variation in packet delay (delay spread) across a stream

Recovery means

Not applicable

Measured by

Measured as packet delay variation (the statistical spread of inter-arrival times) and absorbed by a playout buffer

In electronic circuit design, jitter is the deviation of a signal's transition edges from their ideal moments in time: a clock or data stream whose edges arrive slightly early or late relative to a perfect reference. Da Dalt and Sheikholeslami's Understanding jitter and phase noise treats it as the time-domain face of phase noise and a limit on how fast and reliably links and converters can run. The referent is timing uncertainty in a periodic electrical signal, the identical variability construct found in a voice's glottal cycles and a network's packet arrivals, measured in picoseconds of edge displacement.[3]

Unit

The timing deviation of signal edges from ideal, in picoseconds

Recovery means

Not applicable

Measured by

Measured as period, cycle-to-cycle, or time-interval-error jitter, and related to integrated phase noise