Even the system described by andyjack does not sound reliable.

The system sounded great and we were very pleased with the installation.

The system will sound an alarm if aircraft's altitude is unsafe.

Indeed, the captain also reported the aircraft's stall warning system had sounded.

The other was that the system that should have warned the crew did not sound.

Worse, the system did not sound an alarm to warn when the wrong solution was being used, as some newer machines would.

But the system has been desensitized to avoid crying wolf and often does not sound early enough.

And they used to moan at each other: 'Your system sounds different from my system.

I do wish the audio system sounded a little less flat, but that's just a quibble.

While such a system may sound appealing, in reality it stank.