Four experiments are presented to illustrate the capabilities of vowel Band Grouping and Mutual Exclusion in Vowel Categorization. In the first one an utterance of the five cardinal vowels in Spanish {/a/,/e/,/i/,/o/,/u/} by a male speaker(MS1) in staccato (separating each vowel by a time interval) is used. The purpose is to show how formant bands are grouped in pairs. In the second experiment the same five vowels are uttered by the same speaker(MS1) in legato (leaving no time intervals between vowels).The purpose is to show how vowel boundaries are active in smooth transitions among neighbor and non-neighbor representation spaces.The third experi- ment checks the sentence ‘‘esha´bilunsolodı´a’’ uttered also by a male speaker of Spanish different from the former one(MS2). The purpose is to show the differentiation between vowel-like and non- vowel patterns,and cross-speaker performance(generalization). In the fourth experiment a male speaker of American English(MS3) utters the sentence ‘‘shecanscoop thisthing’’ to showcross- linguistic capabilities, and the competition among close categorical and non-categorical units (see Fig. 5). The results of the four experiments are presented in what follows.