Author Topic: Jitter and Shimmer - Where "in" the signal can I see it?  (Read 2572 times)

Offline zaba

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Jitter and Shimmer - Where "in" the signal can I see it?
« on: November 05, 2014, 06:02:45 AM »
I understand what jitter and shimmer "are", but how can I see them? t

I think jitter can be seen as the jagged nature of e.g. a vowel formant, the little mountains, indicating noise, correct?

But where can I see shimmer?

Offline MalFet

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Re: Jitter and Shimmer - Where "in" the signal can I see it?
« Reply #1 on: November 05, 2014, 07:51:36 AM »
Jitter and shimmer are happening at the scale of frequency peaks, so to "see" them you'd have to be zoomed in pretty darn far. Jitter is the variation between periods and shimmer is the variation between amplitudes over a relatively steady pitch/volume span.

Offline zaba

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Re: Jitter and Shimmer - Where "in" the signal can I see it?
« Reply #2 on: November 05, 2014, 10:37:13 PM »
Thanks! So, my initial statement was incorrect.

Jitter is the frequency of glottal pulses and shimmer is the degree of jagged edges on those pulses.

Accurate?

Offline MalFet

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Re: Jitter and Shimmer - Where "in" the signal can I see it?
« Reply #3 on: November 06, 2014, 05:53:16 AM »
Both jitter and shimmer are measurements of deviation from a "pure" sound. Jitter is the quantity of variation in the frequency of glottal pulses, and shimmer is the quantity of variation in the amplitude.

Offline zaba

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Re: Jitter and Shimmer - Where "in" the signal can I see it?
« Reply #4 on: November 06, 2014, 06:55:30 AM »
ah, in that case, jitter is about the osciliation (somehow linked probably to f0) and shimmer is evident in those little jagged edges on a close-up of a periodic wave.

Offline MalFet

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Re: Jitter and Shimmer - Where "in" the signal can I see it?
« Reply #5 on: November 06, 2014, 06:15:37 PM »
I'm not following what you mean by jagged edges. When you have a lot of variation in amplitude between peaks, that's a lot of shimmer; when the peaks all have very similar amplitudes, that's little.