Figure 6. Auditory threshold shifts (AT2 - AT1) of rats caused by exposure to noise alone (2 h/d, 10 d), toluene alone (6 h/d, 10 d), toluene and noise (6+2 h/d, 10d) and controls. Mean SEM. Dashed curve is the sum of the mean auditory threshold shift in the noise and in the toluene group. * indicate statistically significant interaction (p < 0.05, two way factorial model (GLM: General Linar Models)).