Abstract: The present disclosure relates, according to some embodiments, to devices, systems, and methods for modifying received and/or perceived sound. For example, a device for altering sound received at a subject's ear may comprise an elongated earpiece having a proximal portion and a distal portion and defining a longitudinal axis (e.g., together defining a longitudinal axis). A proximal portion may comprise an insert configured for at least partial insertion in the canal of the subject's ear. A distal end may comprise a handle configured to guide insertion of the insert in the subject's ear canal.