acoustic means of distinguishing between fricatives

Question

I work on data from an under-described language. I am consulting two sources that present phonemic inventories of the same language.

One source posits that the language has a phonemic voiceless velar fricative /x/ and another source says its voiceless glottal fricative /h/. Neither source provides any acoustic data, instead they appeal to their sense of the sounds articulation, i.e. 'feels the constriction is here instead of there'.

A colleague suggested that I just look at the acoustic profile of some samples of the phone in question in praat, and apparently it should be easy to tell.

Phonetics is my weakest area of linguistics, but I do know the basics of praat.

The question is, how would I know what I'm looking at actually corresponds to a velar or glottal fricative?

I've been searching through phonetics resources, but as far as I can tell there doesn't appear to be a sort of "if the formants look like this, and the frequencies are in X range, then you probably have this phone". That does sort of exist for english, which doesn't have velar fricatives.

Is there good a place to start reading on how to match acoustic data to particular sounds as represented by the IPA that aren't only focused on English?

Any suggestions would be helpful.

Answer 1

After some research I believe I can answer my own question now. This page, was a good start.

In short, [x] looks like other fricatives in a spectrogram, the boundaries between [x] and any nearby vowels or sonorants will be more obvious, and there should be a visible band in the upper frequencies that indicates the turbulence in the air-stream. However, less turbulence will be noticeable compared to other fricatives like [s] and [ʃ].

By contrast, [h] in a spectrogram will have trace formants of the adjacent vowels/sonorants. [h] are essentially "voicless vowels", and the airstream turblence in the upper frequencies will be barely, if at all, detectable.

Importantly, detecting either requires good quality recordings. Detecting the turbulence in the upper frequencies can be difficult if there is a lot of background noise in the recording.

Answer 2

This is from my own experience.
In the voiceless velar fricative, there still feels that there is vibration, like one snoring, and that it is more heavy than the glottal fricative.
The voiceless glottal fricative is more airy, and unlike the velar, the back of the tongue touches the back of the mouth, like the slope of a mountain. There is no vibration. It sounds like one panting.
Maybe listen to some words from languages with both of them, like Modern Standard Arabic with both (as light ha and kha respectively) and get a feel for them.