e that there were subliminal messages on those cassettes. Second, There was no ratio for signal to noise that was reported. Signal to noise ratios are needed for the ability to perceive or detect embedded messages. Third, the tapes were described as "signal" or "placebo" cassettes, but he asked the participants to describe if they heard a noise plus a message or a noise alone. Fourth, there was small number of participants of about 8 and yet they were listening to over 300 trials of the tapes, which made their listening skills less effective as they gradually moved on to each trial, which in return made the study less effective. Fifth, none of the participants even had their hearing tested. Sixth, subliminal messages are just that subliminal so if it isn't supposed to be heard then the sound quality doesn't really matter. Seventh, if any of the participants heard anything interesting at all on those tapes, they were never asked to say anything about it.
             In response to Professor Merikle's experiment Eich, Hyman and Urban began their own experiment. They fixed up, what they believed would make this experiment more effective then that of Merikle's. Some specifics they had their experiment were as such: Participants in the experiment were 7 male and 10 female who were introductory psychology students. These participants were informed of the nature of the experiment and were asked to sign consent forms. The participants were exposed to three levels of auditory messages masked with 60-dB, 20-dB and 30-dB. Each participant was presented with 60 trial presentations (10 at each level, randomly mixed; 30 trials in each half).
             The procedure they had in these experiments was that there was two experiment sessions. Each experiment was explained and after every explanation consent slips were signed and obtained again. They were told that if they felt uncomfortable at anytime they were allowed to leave at an...