The sharing economy, which uses digital technologies to share a variety of physical resources in a peer-to-peer manner, has been attracting attention in recent years. There are already widespread services including delivery services using personal cars, accommodation services using private homes, and outsourcing services using each person's spare time. Investigating the feasibility of sharing other types of previous unexplored physical resources in traditional sharing economy services, particularly human bodies, offers promising opportunities with which to expand the current scope of the sharing economy. For example, if other physical resources, such as human senses, could be shared, we might see new possibilities that are different from the current sharing economy services. The contributions of the study are that we propose a novel digital platform named CollectiveEars to share collective human hearing, present its preliminary user studies to extract some current opportunities and pitfalls of CollectiveEars, and show an enhancement of its key abstraction to expand the use cases to explore its possibilities.