Why does the water peak appear at different chemical shift values (ppm) in different solvents in proton NMR spectra? For example, the water peak in DMSO-d6 appears at nearly 3.33 ppm, but the same moisture peak in $\ce{CDCl3}$ appears at 1.56 ppm.
What is the reason behind it? Why should the same species ($\ce{H2O}$) give rise to two different chemical shift values?
