Would the proper term for it really be "non-symbolic language"?
Every language up until now uses symbols at various forms – vowel sounds and consonants are symbols; syllables, which are combinations of vowels/consonants, are symbols; and words, which are combinations of syllables, are symbols, etc.
Would it be possible to create a language with no distinct symbols, and every thought is a gradient of sounds to represent an idea on the "coordinate plane" of thoughts? You could compare the difference between symbollic/non-symbolic languages to the difference between The ideas behind it would be similar to Ithkuil in that you'd be able to represent varying degrees of ideas (AKA, representing the "amount" of heaviness of a rock, for example) very well, however it simply wouldn't rely on symbols.
I admit, someone speaking it would sound hilariously stupid, but is it possible?
I'd be really interested if it is. Some more thought leads me to believe that maybe some degree of symbols is required.
Interpreting this language would be incredibly subjective to the perspective of the listener.
I doubt that I'm explaining this well...