You are correct! The sp hybridized carbon atom has more relative electronegativity than sp² or sp³ hybridized carbon atoms and this gives the attached hydrogen atom some minor degree of positive character...the K_a for acetylenic hydrogen atoms is 10^-24. In the presence of a very strong base such as H₂N^-, an acid base reaction can occur. This generates an organometallic compound that is very useful for organic synthesis.