Friday, August 13, 2021

Roon, EQ and Hearing Loss


Unfortunately for many of us, by the time we can afford our dream systems we are already suffering from hearing loss. You absolutely should see an audiologist if you think you are, however this post is for those of us who have some loss but want to listen without an aid in between our precious audio system and our ears, and in particular how to handle an imbalance in your hearing. 

The ability to do this purely in the digital domain using 32 bit math is a real godsend for us. 

For this project you will need Roon and a set of monotone test tones from about 500Hz to 15,000Hz or so.  I found this page from Demolandia to be perfect for my own needs.  Download all of the necessary files and add them to your personal library in Roon. If you have the time and energy to add some metadata it may help you find them later as well as cleaning up the file names. 

The overall process here is simple: 

  • Identify your worst side.  If music has shifted left then it's your right, and vice versa. 
  • Create a Procedural EQ exclusively for that side. 
  • Play each tone and adjust the EQ until it sounds centered to you. 
  • If some tones shifted to your bad side, repeat for the other side.

Roon has a lot of top-level filters.  Two are easy to get confused:  Parametric and Procedural.  The main difference is that the procedural filters allows you to create a parametric filter for 1 channel at a time. If you use the top-level parametric it will apply to all channels at once.
 
If you have uniform hearing loss then what you want is the Parametric EQ instead of the Procedural.   Think of this as similar to  your basic tone controls. 
 
It's OK to set things up for your own personal convenience. I use the Roon DSP for room compensation, and left to right channel imbalances but I use the Treble control on my integrated to adjust the overall tonal balance for personal taste.

Creating the EQ

Right click on your audio device on the lower right, and select DSP. 


 

On the left the filters will show up.  If you don't see an entry for Procedural EQ, click on the bottom "Add filter":

 

 

Click on Procedural EQ.  On the bottom "Add Operation" will appear. Click it and select Parametric EQ. Now here is the magic.  Click on the Parametric EQ and on the right turn off all the channels EXCEPT the one we are adjusting. In my case my right side is my weakest so leave that on, and left off. 

 Click on the chart area, where I put the red X: 

Now we are cooking with gas! :) 

The default configuration is to have 5 bands with a couple set up to be shelving. You can delete all of them and create new ones or reuse them.  For me, I started with band 3 and went upwards. You can click and drag them or use the numeric entries on the right.  I find the numbers a lot more precise, especially since a difference of 0.2 dB seems audible and affects the centering of the signals.

The next part is a little tricky in selecting the tracks and adjusting the EQ.  The goal is to get each tone to sound centered to you.  As you step through each test tone add a filter with boost where you hear the signal go off center.  I'd leave the Q alone unless you get really fine grained test tones, or feel that you can do more with fewer filters.  In my case my hearing was OK at 1 and 2 KHz but 500Hz and 4kHz needed help so I ended up using 2 filter bands. 

If you listen to multiple rigs you can probably reuse the same settings for all your speakers but that may not apply to your headphones so plan to create a separate set of filters for them.

One last tip:  Enable Headroom Management. This will make it less likely that you'll overload your DAC with clipped digital signal.  Since most of us lose  our hearing in the high frequency range where energy is minimal this is less likely to happen.