Powerhorn doesn't shut off after pressing 0 - is this normal

[mch28]

After tripping the alarm and waiting for it to call the message starts to play and I hit 0 to listen. The powerhorn doesn't stop chirping.  Is this normal operation.  It makes it difficult to hear any noises in the house.

[Tuicemen]

The DS7000 disarms with the pressing of the 0, it only stops the sound from the DS7000 it doesn't send any X10 PLC which is needed for the power horn to stop!

So your Powerhorn is working correctly!
For this reason I don't have a Powerhorn controlled from my DS7000!
Of coarse you could locate your Power horn farther away from the DS7000 perhaps on another floor!