The Dichotic Listening Data In a dichotic listening experiment, subjects wear stereo headphones that allow the presentation of different sound tracks to each ear, at the same time. In this example, right-handed female university students listened to short lectures on art history in the presence of background noise. After each lecture, they answered a set of multiple choice questions. Two factors were varied experimentally: Distraction Type: The background noise consisted of either Hip-hop music, Classical music or Radio commercials. Volume was carefully held constant. Presentation : Subjects heard either * Lecture (Signal) in the left ear and distraction (Noise) in the right -- at the same time * Distraction (Noise) in the left ear and lecture (Signal) in the right -- at the same time * Both Signal and Noise in both ears at the same time Each subject in the experiment experienced all nine treatment combinations, in a balanced order that was different for each subject, and randomly assigned. Thus, there are nine data values for each subject: number of questions answered correctly in each experimental condition. The raw data appear below, along with my SAS variable names (test11, etc.). Signal in Signal in Signal in Left Ear Right Ear Both Ears ____________________ ____________________ ____________________ HipHop Classc Radio HipHop Classc Radio HipHop Classc Radio ------ ------ ------ ------ ------ ------ ------ ------ ------ test11 test12 test13 test21 test22 test23 test31 test32 test33 1 13 12 10 15 14 14 14 13 14 2 4 8 8 6 5 8 6 3 4 3 13 15 11 11 13 15 11 13 12 4 7 5 4 6 7 3 6 7 6 5 11 12 14 9 11 8 12 10 11 6 11 10 10 8 7 9 8 10 7 7 5 5 10 4 3 4 9 8 8 8 12 11 10 12 11 8 13 13 11 9 14 9 12 9 9 6 9 16 7 10 8 6 5 7 11 4 6 6 6 11 11 8 12 9 9 9 10 12 9 12 10 13 11 10 11 10 10 11 13 13 12 7 10 11 13 8 12 10 13 14 4 7 6 7 6 8 6 8 6 15 12 9 10 10 9 10 9 9 6 16 9 5 6 8 9 5 6 5 5 17 8 14 14 11 11 11 10 9 8 18 6 5 7 8 5 6 6 8 4 19 12 12 8 12 12 10 11 14 9 20 7 7 6 8 10 8 6 5 5 21 13 7 5 5 7 10 8 7 9 22 7 8 12 8 10 11 7 9 8 23 9 9 12 12 9 11 11 9 9 24 12 13 14 15 15 11 14 10 10 25 4 4 2 3 7 4 3 4 5 26 9 13 12 12 11 7 7 11 6 27 10 12 10 14 13 9 13 13 10 28 8 10 13 13 13 9 8 10 11 29 12 10 6 11 6 7 6 7 5 30 12 11 12 13 12 11 10 11 11 31 13 12 11 9 14 12 13 14 13 32 10 7 7 6 9 8 7 9 8 33 12 12 11 14 10 10 11 10 10 34 10 9 8 11 12 12 10 10 11 35 15 11 10 13 12 11 12 12 11 36 11 14 9 11 9 8 11 8 8 37 8 10 14 10 15 10 11 10 10 38 7 6 5 8 8 8 6 5 6 39 10 9 5 6 12 5 5 9 9 40 5 6 8 5 9 5 6 9 4 41 12 13 8 12 11 12 8 8 7 42 8 9 7 8 9 7 5 8 6 43 7 7 9 8 7 11 7 9 9 44 13 12 9 9 12 10 10 10 10 45 4 6 6 6 4 5 4 3 5 46 9 8 10 9 14 14 8 12 11 47 7 8 7 9 7 9 7 5 6 48 15 14 13 15 16 15 12 12 11 49 6 10 8 5 7 6 5 4 7 50 4 6 6 4 4 8 5 10 5 51 5 9 6 11 9 9 8 8 12 52 10 10 8 11 11 8 8 12 9 53 5 5 5 4 7 4 11 10 9 54 11 11 11 14 9 8 8 7 9 55 7 5 9 6 6 11 7 7 8 56 15 14 14 15 17 12 16 16 15 57 12 7 7 9 8 7 7 9 5 58 10 11 11 9 10 9 12 14 8 59 9 10 11 11 10 11 9 9 8 60 7 9 8 6 8 8 9 6 6 61 11 15 16 10 14 15 13 13 16 62 12 7 9 9 9 9 9 9 8 63 10 13 9 7 9 8 9 7 7 64 7 7 8 4 5 5 6 11 6 65 9 12 9 7 11 10 11 8 10 66 14 14 11 12 13 11 12 15 12 67 9 3 9 8 5 4 5 6 4 68 15 17 13 14 11 15 11 14 13 69 9 10 7 7 8 9 6 9 7 70 10 9 11 11 8 8 9 9 9 71 6 7 6 5 7 5 6 5 5 72 5 5 8 7 9 5 7 6 8 73 11 15 8 10 11 11 11 10 9 74 15 19 20 16 18 18 17 19 18 75 6 5 5 4 3 3 4 4 3 76 11 11 11 10 13 11 11 10 11 77 6 9 8 5 5 7 7 7 5 78 6 11 9 6 8 6 7 6 13 79 8 10 6 7 9 14 10 7 9 80 8 8 6 7 8 11 10 10 7 81 15 13 13 11 13 13 11 13 10