X0206 3/A 2021-02-11 2021-02-11 0 0001656536 Decibel Therapeutics, Inc. DBTX 0001620014 Exter Neil C/O DECIBEL THERAPEUTICS, INC. 1325 BOYLSTON STREET, SUITE 500 BOSTON MA 02215 1 0 1 0 Common Stock 47169 I See footnote These shares were omitted from the Reporting Person's original Form 3. Held of record by Third Rock Ventures III, L.P. ("TRV III"). The Reporting Person is a partner of Third Rock Ventures GP III, L.P., which is the general partner of TRV III. The Reporting Person disclaims beneficial ownership over such shares, except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that he is the beneficial owner of such shares. /s/ Ronald Vigliotta, Attorney-in-Fact 2021-02-19