A passage of sound is recorded on to an electronic storage medium (12) for inclusion within a sound storage device (6, 7, 8) which is selectively engageable with an arbitrary physical object. This engagement can be provided by a number of conventional means: a spring loaded clip (particularly suitable for engagement with objects), a weakly adhesive surface, or a magnetic element. The passage of sound may then be read from the sound storage device while it remains engaged with such an arbitrary object using an appropriate sound reproduction device (4). This arrangement allows sound passages to be used in a very versatile fashion, particularly for annotation and messaging.