Note Onset Detection Dynamic Thresholding

So I am working on Note Onset Detection. I have implemented the method here: Note onset detection

However, I am finding some difficulty or problems regarding the 'static' nature of the method. What I am looking for is how to make the thresholding method 'dynamic'. But I am finding trouble finding suitable solutions.

Aside from that, I am also working on instead of having the amplitude value as the basis of passing the threshold, I make use of the 'difference' between 2 amplitude values, to know when a signal increases or not, and how much it increased or decreased. This is what I'm using currently.

Anyone willing to help or has worked with this kind of problem? Thank you!

Additionally, by any chance do a开发者_StackOverflow社区ny of you have a PDF file of this paper: http://www.mendeley.com/research/methods-detecting-impulsive-noise-speech-audio-signals-14/

Volume compression is a form of AGC (Automatic Gain Control), and AGC can be done dynamically. The are plenty of close to real-time AGC algorithms to be found in search results, although a bit of delay is required if you want an AGC attack that's smoother than a step function.