# How to read these vowel diagrams?

I've come across a couple of vowel diagrams. Here one:

Here's another:

I'm not really sure how to interpenetrate these charts. Any ideas?

In pronouncing any given vowel, the recorded frequency spectrum will show distinct amplitude peaks (of the frequency spectrum). These peaks are called formants, and it is commonly accepted that the two lowest frequency formants taken together are enough to characterise the vowel.

The first formant F1 is the lowest frequency formant, and the second formant F2 is the second lowest frequency formant, etc.

Spectrogram of American English vowels [i, u, ɑ] showing the formants F1 and F2. The darkness of the band corresponds to the height of the amplitude/frequency plot; darkest areas show local peaks. From https://en.wikipedia.org/wiki/Formant#/media/File:Spectrogram_-iua-.png

The F1 frequency (range) corresponds to the perceived openness/height of the vowel, and the F2 frequency (range) corresponds to the perceived backness of the vowel.

Wikipedia IPA vowel chart

To demonstrate the effect of the F1 and F2 components on vowels, you can use artificial vowel generators which take these parameters to produce audible vowels, e.g. http://auditoryneuroscience.com/vocalizations-speech/two-formants.

As an example, consider the

• Chengdu /o/ sound, which the graph says is at F1 ≈ 440, F2 ≈ 600 Hz

• Pengzhou /o/ sound, which the graph says is at F1 ≈ 550, F2 ≈ 875 Hz

The corresponding artificial vowels are (unmute the audio in the imgur image)

Produced from auditoryneuroscience.com with a fundamental frequency of 110 Hz

• Your answer is great with the images and the audios! As you can see in the graph, the vertical straps correspond to the amplitude frequency spectrum. The darker its color, the stronger its amplitude. The graph is acquired through Short Time Fourier Transformation. – Toosky Hierot Nov 28 '19 at 15:23
• @TooskyHierot thank you, you're right that I should mention the darkness of the bands as corresponding to the peaks. This is not obvious to a non-engineering or science person. – dROOOze Nov 28 '19 at 15:35

The scientific terms are in bold font... If you are interested you may google them.

• Your writing style isn't like the mainstream of modern Chinese. – dan Nov 27 '19 at 23:30
• 術語用多的時候，可否提供些維基鏈接，提升答案的易讀性？ – dROOOze Nov 28 '19 at 4:52
• @droooze Sorry for that, because I learned it in class, here I just write down what I know...... – Toosky Hierot Nov 28 '19 at 15:04
• It's hard to understand the whole graph without adequate math knowledge... In other words, I cannot decide put what links in my answer... – Toosky Hierot Nov 28 '19 at 15:07