Amazing new study reveals unborn babies 'sing and dance' to music New research in Spain proves that unborn babies can hear and respond to music at just 16 weeks, ten weeks earlier than previously thought, but only if played through a 'musical tampon'. http://www.thelocal.es/20151007/foetus-responds-to-music-at-16-weeks-in-world-first
If the kiddo's have higher bpm, thrash or speed metal's good for 'em. Heart rate in small kids are usually higher, right? Other potential uses: getting rid of constipation?
All internal organs of human beings respond to musical vibrations. The US military had at one time - maybe still has - a serious research project into the effects of projected sound on the wellbeing of targeted people - certain low pitched tones showed promise for riot control, etc. https://en.wikipedia.org/wiki/Sonic_weapon