Process Definition - Based on Any Change to a Specific Field

I'm trying to receive a notification any time there is a change to one specific field in the Account module. It's an open text field, and I need to know whenever it is changed/updated. The best I've been able to come up with is being notified whenever anything on the account is updated (which can be a lot), and in the email template, I have the field's old and current values. It just creates extra emails for me to wade through, so I'm hoping there's a way to get notified only when a specific field changes.