If your referring to the Hospital Wing ops MedCom-
Hospital Wing Memphis
Frequency License Type Tone Alpha Tag Description Mode Tag
155.28000 KNHY227 BM 156.7 PL Dispatch, Flight Following FM EMS Dispatch
463.15000 KNHY227 BM 151.4 PL Dispatch, Flight Following FM EMS Dispatch
155.34000 KNHY227 M Ground-to-Air HEAR FM Hospital
155.20500 KNHY227 M Ground-to-Air State EMS FM Interop
From the DeSoto County MS page, verified when I lived in Memphis for a while..
155.20500 KNHY227 BM EMS toMedCom EMS to Med Com Dispatch Memphis FM Hospital
If your referring to the non trunked freqs for Hospital MED communications see the Emergency Services section on this page-
Shelby County, Tennessee (TN) Scanner Frequencies and Radio Frequency Reference
On many of these, if you get a good ducting event then yes you could hear these.