A head-mounted wearable device assembly is provided that includes a bone conduction transducer (BCT) and an elastomeric isolation member that provides acoustic isolation between the BCT and a housing of the head-mounted wearable device assembly. The elastomeric isolation member may be a polyurethane material having a hardness (durometer) on the order of 60 A. The material arrangement and durometer may be chosen to provide a frequency response and/or acoustic leakage within a predetermined range, which results in high quality sound reproduction for the wearer. The elastomeric isolation member may be secured to an interior portion of the housing by a pair of mounting posts. The elastomeric isolation member physically and acoustically separates the BCT from the interior of the housing and other components therein.