Hansen (2012) has found in a study of expert, amateur and non-musicians, that expert musicians have an enhanced verbal working memory. Verbal working memory is a short term memory cognitive memory functions which allows us to temporarily store information, and ultimately supports the memory storage process. Musicians have been found to have enhanced verbal long term and short term memory function (Brandler and Rammasayer, 2003; Chan, Ho, & Chung, 1998; Franklin et al., 2008; Jakobson, Lewychy, Kilgour, & Stoesz, 2008; WM Franklin et all., 2008; Lee, Lu, & Ko, 2007; Tierney, Bergeson, and Pisoni, 2008; Wallnetin, Nielsen, Friis-Olivarius, Vuust, & Vuust, 2010a, 2010b).
Verbal working memory is assessed through the use of a digit span test. A random series of letters are shown to the participant and the the participant has to verbally recall each letter in correct order. The sequence of letters to be recalled is increased by one digit (letter) each time. The test is discontinued when the participant fails on two trials of the same digit length. The digit span test is done in forward order (recalling the digits in correct order) and backwards order (recalling the digits in reverse order).
Expert musicians in the Hansen (2012) study exhibited greater verbal working memory capacity than non-musicians. Suggestions for these results include the ability of musicians to mentally rehearse auditory stimuli, similar to aural recall of melody and rhythm often done by musicians when learning by ear. The digit span test requires participants to attend to auditory imagery (presentation of a digit) and determine the temporal order of the items in auditory working memory to be able to recall the items correctly. This is a subvocal rehearsal strategy said to be similar to that employed by musicians in the scanning and rehearsal of music. Musicians are less likely to confuse the temporal order of verbal material in working memory.
Other suggestions include superiority of musicians to recall auditory stimuli. Musicians have been found to have superior of linguistic intonation, lexical stress, lexical tone and speech in noise, thus the enhanced ability to discriminate auditory sounds might further enhance the superior auditory recall of musicians.
Musicians have also been found to activate more neural subnetworks of auditory capacity than non-musicians. FMRI have revealed that musicians activated two neural subnetworks in addition to core networks in a study of rehearsal and storage of verbal and tonal material. This suggests than expansion auditory storage capacity occurs in the training of music through use and improved efficiency.
Source: Hansen, Wallentin & Vuust (2012). Working memory and musical competence of musicians and non-musicians. The Psychology of Music 41(6) 779-793.