  Based on doubly detuned Raman transitions between (meta) stable atomic or
molecular states and recently developed atom counting techniques, a detection
scheme for sound waves in dilute Bose-Einstein condensates is proposed whose
accuracy might reach down to the level of a few or even single phonons. This
scheme could open up a new range of applications including the experimental
observation of quantum radiation phenomena such as the Hawking effect in sonic
black-hole analogues or the acoustic analogue of cosmological particle
creation. PACS: 03.75.Kk, 04.70.Dy, 42.65.Dr.
