Tell me about which alert is firing off the same symbol at times.
I ask because there are several ways to deal with this:
1. Many alerts have an alert-specific filter next to them where you can dial up the threshold before an alert is generated (e.g., Running Up alerts that use a ratio or imaginary dial from 2-10, etc.)
2. Another way to filter out the number of times is by adding an additional filter or increasing an existing filter you have. (e.g., increasing the Min Current Vol filter to a higher number will ensure you only see alerts on higher than usual volume)
3. You can also use our Min and Max count filters. I know this doesnt exactly fit your request of appearances/minute, but it can be useful. Also look at the heartbeat alert which is the only alert that acts in the manner you describe.