Audibly

adv. [f. as prec. + -LY².] In audible manner, so as to be heard, aloud.

1635.  Jackson, Creed, VIII. xxix. 338. All the rest … had been visibly and audibly fulfilled.

1805.  Southey, Madoc in Azt., XIII. Wks. V. 287. Which made her heart with terror and delight Throb audibly.

1860.  Tyndall, Glac., I. § 11. 80. Audibly muttering his doubts as to our ability to reach the top.