It is possible to sing, growl, and engage in other vocalizing while simultaneously playing the tuba in a traditional capacity. The general effect on the vocalized component is one of muffling timbre and obscuring articulation. In some cases, this allows for a more natural blend of vocal and tuba phonation in the resulting multiphonic.
Pitch range. Vocal range depends on the performer in question (gender and fach). Tuba range is as normal.
It should be noted that many of the same muscles used to change embouchure are used in the production of vocal phonation. Changing the pitch of one may result in an undesired, but physically unavoidable, shift in the other. It is especially difficult to sing below the phonated pitch. Simply put, register and context are everything. It is highly recommended, therefore, that all examples be checked with the performer in question beforehand. In some cases, a given simultaneity or phrase might become possible with practice; in others, not.
Dynamic range. pp–ff.