# Creating Specific Intensity Change

I am trying to create a 440 Hz sine wave tone with changing intensity. Specifically, the intensity should change according to the inverse square law (1/x^2 where x is equal to time). I would appreciate any advice!

What do you mean by “intensity”, or in other words, what is “y” in your equation?
Possible options:

• Amplitude
• RMS amplitude
• Energy
• Power
• Loudness
• Other

Time in seconds? Minutes? Samples? Other?

My bad. Intensity as power, and time as seconds.

That would just be a linear (amplitude) fade wouldn’t it?

I have used the linear fade before, but in this case, I want the rate of change to be non-linear. How can I specify a non-linear change?

That’s “linear amplitude”, so I’ll assume that you want:

``````g = 1/t^2
``````

Where g = gain and t = time in seconds.

What do you want to do when t = 0?
Is there a purpose for this? How accurate does it need to be?

That would be Generate > Tone > Sine > 440. Then any number of fade in/out effects can be created here: Effect > Fading > Adjustable Fade

Steve, of course, may be happy to personalize an effect just for you.

That’s “linear amplitude”, so I’ll assume that you want:

g = 1/t^2

``````>
> Where g = gain and t = time in seconds.
>
> What do you want to do when t = 0?
> Is there a purpose for this? How accurate does it need to be?

When t=0, I just need it to be the highest dB of the sound. The remaining dB just needs to be relative to t=0 (simulating an approaching sound).

I get errors when running regarding the equal sign ("parse error: Not an expression or symbol.")

```text
g = 1/t^2
return *track*[code]
``````

Is that what this is about?
If so, then you need an exponential decay / rise. The “Adjustable Fade” effect has a preset for that.

Yes