Jitter & Shimmer Calculator
Jitter and shimmer are classic acoustic perturbation measures. Jitter reflects cycle-to-cycle variation in fundamental frequency, while shimmer reflects cycle-to-cycle variation in amplitude. Elevated values are associated with roughness and hoarseness and are commonly reported in clinical voice assessment.
Open the Jitter & Shimmer Calculator →How to measure jitter and shimmer
Record a steady sustained vowel (for example /a/) in a quiet room. Vocametrix extracts the perturbation measures automatically and lets you export them, so you can document vocal stability over time.
Interpreting the values
Jitter and shimmer require a reliably periodic signal, so they are most meaningful on mild-to-moderate dysphonia and sustained vowels. For more severe voices, robust measures such as CPP or AVQI are often preferred.
Frequently asked questions
What recording do I need for jitter and shimmer?
A stable, sustained vowel recorded in quiet conditions gives the most reliable jitter and shimmer values.
Is this an alternative to Praat for jitter/shimmer?
Yes. Vocametrix computes jitter and shimmer online without requiring you to install Praat or write scripts.