The .Tone file in an iPod is meant to tell the system what sounds to play from the speaker when the alarm is set. Tone files are actually just txt files that are structured so that the iPod can understand what pitch to play and for how long.

How to Edit Tone Files

As of writing, there is only a single Instructables guide on how to edit tone files. So, both a guide and a link to the only other guide online will be posted here:

• First, you must have your iPod in disk mode. See the iPod FAQ on a guide on how to enable Disk Mode.
• Next, open the iPod storage device and find the file titled Beep.tone.
• It is recommended that you duplicate the file. You can also change the file name from .tone to .txt.
• Open the file within any txt file editor of your choosing.

Now, you are at a point where you can start editing the file. The name at the top is the alarm sound name that the iPod will display regardless of what the file name is. The first digit on the left represents the frequency of the sound in hertz. The second digit represents how long that frequency will be played (in Milliseconds).

Note: the Instructable guide warns against differentiating in ± 100 Hz in the sounds due to the possibility of breaking your iPod's speaker. This may or may not be true, but only change these values at your own risk.

Then you can select the newly created tone file once you select it within your iPod.

Instructables Guide Link: https://www.instructables.com/Install-RockBox-on-an-iPod-easy-steps/