A protective cover for an electronic device (102, 608), the protective cover comprising: a case (100, 600) for enclosing the electronic device (102, 608), the case having an inner surface, an outer surface, and a hard shell (110, 112, 606) that encapsulates the electronic device (102, 608), the hard shell (110, 112, 606) having a shell opening (610, 624) in the case approximately aligned with an acoustic opening (612, 626) of the electronic device (102, 608) when the electronic device (102, 608) is installed in the case (100, 600); a removable silicone cover (614, 628) configured to be fitted over the hard shell, the removable silicone cover (614, 628) having an acoustic isolation mechanism (616, 634) installed into the shell opening (610, 624) of the hard shell proximate the acoustic opening (612, 626) of the electronic device, wherein the acoustic isolation mechanism (616, 634) is molded from a waterproof elastomer and comprises: an interior face oriented towards an interior of the case and an exterior face oriented towards an exterior of the case, the exterior face contacting the inner surface of the case, at least one acoustic channel (704, 804, 904, 1115) extending from the interior face to the exterior face of the acoustic isolation mechanism that acoustically couples the electronic device and the shell opening (610, 614), and at least one acoustic membrane (710, 810, 910, 1110, 1302) that spans a cross-section of the at least one acoustic channel, and wherein the at least one acoustic membrane (710, 810, 910, 1110, 1302) is molded from the waterproof elastomer of the acoustic isolation mechanism (616, 634). a case (100, 600) for enclosing the electronic device (102, 608), the case having an inner surface, an outer surface, and a hard shell (110, 112, 606) that encapsulates the electronic device (102, 608), the hard shell (110, 112, 606) having a shell opening (610, 624) in the case approximately aligned with an acoustic opening (612, 626) of the electronic device (102, 608) when the electronic device (102, 608) is installed in the case (100, 600); a removable silicone cover (614, 628) configured to be fitted over the hard shell, the removable silicone cover (614, 628) having an acoustic isolation mechanism (616, 634) installed into the shell opening (610, 624) of the hard shell proximate the acoustic opening (612, 626) of the electronic device, wherein the acoustic isolation mechanism (616, 634) is molded from a waterproof elastomer and comprises: an interior face oriented towards an interior of the case and an exterior face oriented towards an exterior of the case, the exterior face contacting the inner surface of the case, at least one acoustic channel (704, 804, 904, 1115) extending from the interior face to the exterior face of the acoustic isolation mechanism that acoustically couples the electronic device and the shell opening (610, 614), and at least one acoustic membrane (710, 810, 910, 1110, 1302) that spans a cross-section of the at least one acoustic channel, and wherein the at least one acoustic membrane (710, 810, 910, 1110, 1302) is molded from the waterproof elastomer of the acoustic isolation mechanism (616, 634). an interior face oriented towards an interior of the case and an exterior face oriented towards an exterior of the case, the exterior face contacting the inner surface of the case, at least one acoustic channel (704, 804, 904, 1115) extending from the interior face to the exterior face of the acoustic isolation mechanism that acoustically couples the electronic device and the shell opening (610, 614), and at least one acoustic membrane (710, 810, 910, 1110, 1302) that spans a cross-section of the at least one acoustic channel, and wherein the at least one acoustic membrane (710, 810, 910, 1110, 1302) is molded from the waterproof elastomer of the acoustic isolation mechanism (616, 634).