This talk presents hands-on activities to give intermediate students experience conducting phonological perception experiments and deepen their grasp of categorical consonant perception. It focuses on two assignments in which students gather categorical perception responses from friends, graph them to reveal crossover points, form hypotheses about contributing cues, and apply Praat measurement skills to test them. In the first, students and naïve friends respond to online phoneme identification and discrimination tasks involving a synthesized /ba-da-ga/ continuum varying only in formant transitions. They tally and graph the pooled responses, identify crossover points, and answer interpretation questions. In the second task, students and friends identify words on a bad-bat continuum varying only in vowel length. They hypothesize which phonetic features might distinguish the words, then measure them in Praat to discover that vowel length cues final consonant voicing, not voice onset time as learned in previous lessons. These activities have been used successfully in an advanced introduction to speech science for speech-language pathology undergraduates with an introductory English phonetics prerequisite. They form many students’ first experience conducting experiments, and the hypothesis, deduction, and interpretation portions stretch their critical thinking skills.