Broca's heirs, though, now have a range of new techniques with which to investigate the question. The best-known is a way of scanning the brain called functional magnetic-resonance imaging (fMRI).

Only little differences in the frequency range under 1 MHz at different current peak values (Fig. 14 and Fig. 15) can be noticed except from some resonance frequencies.

You will also be engaging your diaphragm more, and this in turn will the lower end of your voice range and add resonance to your voice, conveying more authority.