I've been developing and idea for a book to write. I wanted the aliens to speak with a different vocal anatomies than humans. The aliens in subject, the "Uudra", possess no tongue, instead and inner pair of mandibles in which allows clicking and "chirring" consonants but also the lack of vowels.
The following are the sounds that the Uudra can produce. The symbols used are IPA symbols that I've tried to match as accurately as I can:

Obstruents:
ǃ alveolar click, ǃː alveolar chirr
χ/ħ uvular/pharyngeal click*, χː/ħː uvular/pharyngeal chirr*
ǁ lateral click, ǁː lateral chirr
ʘ bilabial click,
Lateral:
̢ɬ retroflexed lateral fricative (hiss)
Sonorants:
ʁ uvular fricative (grunt), ʀ uvular trill (growl)

ˤ, ˩, ˨, ˧, ˦, ˥ glottal tones

I'm not sure if the above makes sense for the average linguist so I could use all of your input, thanks

The IPA was specifically developed to represent sounds produced by a human vocal apparatus. You would need an entirely novel system to represent the sounds produced by a truly alien vocal apparatus, with a correspondingly novel set of terms. For instance, alveolar sounds are produced with the tongue against the alveolus, or gum ridge. If these aliens don't have teeth, then they don't have gums or gum ridges--and you've already said that they don't have tongues. Thus, it makes no sense to characterise one of the sounds they produce as an "alveolar click".

If I were you, I would read up on insect anatomy and see what terminology entomologists use to describe insect vocalisations.

Thats an interesting idea. Someone should create a sort of "International Priori Alphabet" or something like that to represent languages spoken by aliens. You could include it in your book or something.

You might be interested in _The Jupiter Theft,_ by Donald Moffitt. Moffitt creates aliens with extremely complex tongues, resulting in the ability to create an extremely varied set of phonemes sounding musical to the human ear.

(Unfortunately, the novel itself isn't very good.)

Very interesting idea, I wonder if you could apply the Sapir-Whorf hypothesis to this, how would beings which do not and can not communicate in a 'human' fashion think? How would their culture evolve?

Wow, that's a lot of input to sift through

I probably shouldve given more details about their vocal anatomy; though the Uudra have no tongue, they have a second pair of mandibles in its place to swalllow food, the rest of their basic mouth structure is similar to ours, possesing lips, teeth and gums, an alveolar ridge, a palatte, a uvula, a pharynx and a larynx. With the secondary manbibles, or "inferior mandibles", they can be used to constrict air at points of the alveolus, the lateral, the uvula, and the pharynx. Their movment can be a single plosive movement off of these surfaces (known as clicks), or a rapid vibration against the surfaces (known as chirrs). But the lack of a malleable structure such as a tongue denies them the capability of producing differing vowels. They can simultaneously "voice" by vibrating their glottis at differing speeds to produce the glottal tones.

I looked up insect communication and learned that insects dont "vocate" since they dont have a respiratory system like our own that allows us to vocate. Instead some "stridulate" (rubing body parts together), or in the case of cicadas, have a organs called "timbals" - I like the idea of timbals, but I dont know how I can add that to the already developed Uudra physiology :S

As for creating IPA symbols for alien sounds, the whole idea of my use of IPA symbols was to help understand the vocal structure and sounds the Uudra possess. The Uudran writing would be considered as their IPA.

As for the rest, I'll have to go over in more detail...