We had the case in MEG that some alarms were actually just warnings, not very severe. This happens for example if we calibrate our detector 
once every other day and modify the hardware which actually triggers the alarm for about an hour or so.

The problem with this is now that the alarm sounds every few minutes, and people get annoyed during that hour. They turn down the volume 
of their speakers, or even disable the alarm sound. If the detector gets back into the default mode again, they might forget to re-enable the 
alarm, which causes some risk. 

Turning down the volume is also not good, since during that hour we could have a "real" alarm on which people have to react quickly in order 
not destroy the detector.

The art is now to configure the alarm system in a way that "normal" changes do not annoy people or cover up really severe alarms. After long 
discussions we came to following conclusion: We need a special class of alarm (let's call it 'warning') which does not annoy people. The 
warning should be visible on the screen, but not ring the alarm bell. 

While we have different alarm classes in midas, which let us customize the frequency of alarms and the screen colors, all alarms or warnings 
ring the alarm sound right now. This can be changed in the browser under "Config/Alarm sound" but that switch affects ALL alarms, which is 
not what we want.

The idea we came up with was to add a flag "Alarm sound" to the alarm classes. For the 'warning' we can then turn off the alarm sound, so 
only the banner is shown on top of the screen, and the spoken message is generated every 15 mins to remind people, but not to annoy them.

I added this "Alarm sound" flag in the branch feature/alarm_sound so everybody can test it. The downside is that all "Alarm/Classs/xxx" need 
to be modified to add this flag. While the new code will add this flag automatically (with a default value of 'true'), the size of the alarm class 
record changes by four bytes (one bool). Therefore, all running midas programs will complain about the changed size, until they get 
recompiled. 

Therefore, to test the new feature, you have to checkout the branch and  re-compile all midas programs you use, otherwise you will get errors 
like 

  Fixing ODB "/Alarms/Classes/Alarm" struct size mismatch (expected 352, odb size 348)

I will keep the branch for a few days for people to try it out and report any issue, and later merge it to develop.

Stefan