Advanced
Technical
IVT
shimmer
Acoustic parameter measuring cycle-to-cycle variation in vocal amplitude, used to assess voice quality and laryngeal pathology.
Full Definition
Shimmer quantifies the perturbation in vocal amplitude (loudness) from one vocal fold vibration cycle to the next during sustained phonation. It is typically expressed as a percentage or in decibels and serves as an indicator of vocal fold mass lesions, neurological impairment, or other pathological conditions affecting voice production. Normal shimmer values are generally below 0.35 dB for healthy voices, with elevated values suggesting voice disorders requiring clinical intervention.
Usage
Usage note: Specify measurement units (dB or percentage) and include reference values for clinical interpretation.
In Context
- "The patient's shimmer value of 0.8 dB exceeded normal limits, indicating amplitude instability." — Acoustic analysis report
- "Voice therapy resulted in shimmer reduction from 1.2 dB to 0.4 dB over twelve sessions." — Progress documentation
Also known as
amplitude perturbation
Don't confuse with
jitter
tremor