By G8MNY (New Apr 17)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)
While laying around for a week in Hospital & a noisy night time drug pump Alarm on the adjacent bed, I found myself playing sound games when I could not sleep.
┌────────────────────────────────────────┐
│ Bed │
│Bed▒▒▒▒ ▒▒▒ ▒▒▒▒Bed│
│ ▒▒▒ │________
│
│ Corridor
│ ________
│ ▒▒▒ ▒▒▒ ▒▒▒ │
│ ▒▒▒ [] ▒▒▒ ▒▒▒ │
│ Bed Alarm Me Bed │
└────────────────────────────────────────┘
I was in the middle of a 6 bed ward. The alarm was a loud pure note (1.5kHz?)
& I found with my head on one side & moving just a few mm, I could get a VERY deep nulls (60dB) in the tone from the reflections bouncing up & down the room.
Then when the nurse approached from the corridor, I could detect this with the standing wave reflections were being disturbed. This gave a loud multiple Doppler ping sounds for each node the nurse went through.
All quiet interesting when you have nothing else to do in Hospital at night!