Any past or disappearing sound remembered nostalgically, particularly when idealized or otherwise given special importance. Whereas new sounds are often experienced as sound phobias, old or past sounds are often elevated to the category of sound romances in memory. Many such sounds were often regarded as unimportant when actually current; yet later, hearing them may trigger strong memories.
Sounds experienced during childhood, for instance, often become romances for the adult. After moving away from a given area, particularly one strongly linked with sound, such as a community by the ocean, to a place lacking those familiar sounds, these may also acquire a romantic or nostalgic quality. Other sounds go beyond having only personal romance qualities and are valued and preserved by a society as soundmarks.
(Source - Barry Truax - Handbook for Acoustic Ecology CD-ROM Edition. Cambridge Street Publishing, 1999 - CSR-CDR 9901)