Changing the volume of individual tracks


I have the current version of Audacity.

I am an Audiologist and am looking to integrate two separate CDs that I use for testing hearing of speech.

I have already combined the two CDs but there is a problem.

Each CD has different volumes. The first track of each CD is a calibration tone. We use this calibration tone to set the volume of the audiometer (machine used for the testing).

As it stands now, the calibration tones are different in volume. This means that the corresponding tracks are also at different volumes. For me to do the testing appropriately I have to play the first calibration tone, adjust the volume level of the audiometer, play the corresponding tracks. For the second phase of the test, I have to play the other calibration tone, adjust the volume level of audiometer again and then play the corresponding tracks.

I would love to be able to use Audacity to change the volume of one set of tests so that both can be equal in volume and allow me to skip the step of having to adjust for two different calibration tones.

Can I use Audacity to do this?

Thanks in advance for any advice.

You can look at the sound meters to figure out how to fix this, but I would make them enormously larger by clicking on the right-hand edge and pulling sideways.

Note the meter dB values of the two calibration tones. Select the low clip (by double clicking on it) and bring it up with Effect > Amplify > Amplification: difference between where you are now and where you want to be. It works the other way, too. It’s probably safer to bring the high one down. Slightly low is correctable. Too high can cause fatal damage.

For example, if they’re 6dB different on the meters, amplify the low one by 6dB or cut the high one by using a negative number, -6dB.


This code can be run in the “Nyquist Prompt” effect (in the “Effect” menu).
It will show the peak amplitude of the selected audio (in dB) accurate to 4 decimal places.

(defun printdb (sig)
  (linear-to-db (peak sig ny:all)))

(if (arrayp s)
    (format nil "Left Channel: ~a dB.~%~
                Right Channel: ~a dB."
                (printdb (aref s 0))
                (printdb (aref s 1)))
    (format nil "Mono Trackl: ~a dB." (printdb s)))