The medium may be an organometallic gaseous medium.

The carrier is optionally hermetically sealed.

The support may be a post.

The support may be essentially free of alumina.

The backing may be rigid or flexible.

The carrier may be a polymeric material.

The support may be a foldable frame.

The holder is manually removable from the container (2) and the stirrer is manually removable from the holder for cleaning.

The carrier is removable from the carrier receiving support.

The bracket is connectable to the attachment point.

The medium can be pre-recorded or recordable.

Food additives to which the carrier may be added

Thus, the holder can be released from the handle and the holder can be coupled to the handle in a simple manner without much effort.

The carrier can be non-aqueous, and can comprise a film forming material.

The support can be configured to couple the transducer to the sound window such that the support can be removed from the round window.