From a study by Milovanov R, Tervaniemi M, Takio F, and Hämäläinen H:
To increase our understanding of the phonemic processing skills of musical and non-musical subjects, the Dichotic Listening task was performed in children and adults with varying degrees of musical aptitude. The roles of maturation and musical training were also investigated. The results showed superior left ear monitoring skills among the adults who practised music regularly. This may indicate altered hemispheric functioning. Other musically talented subjects did not have the ability to control left ear functioning in an equal manner, for instance, the performance of musical children and their non-musical controls in the forced-left / left ear condition did not differ. Thus, regular music practice may have a modulatory effect on the brain’s linguistic organization and therefore, the beneficial effects of music on other cognitive skills should not be underestimated [emphasis added].
This hearkens back to Milovanov et al.’s earlier study showing that musical and linguistic skills share neural mechanisms. Here we see that in addition to neural reorganization where linguistic processes occur, we also have superior left-ear monitoring. What differentiates this study is that the effects are more pronounced in adults, who presumably have had more time to reorganize their brains. So regular practice throughout a lifetime continues to accrue linguistic and hearing benefits in the brain. If you learned to play an instrument as a child, and haven’t practiced in a while, it’s time to blow the dust off your instrument and start practicing again–you may just be pleasantly surprised at what ten minutes, twice a day, can do for your brain.
The other point made in this study is that music training may have larger benefits than just on language-related skills, but may in fact positively influence all cognitive skills. Does Mozart make you smarter? Playing Mozart just might!