Hi @ooshock, thank you for reaching out, and welcome to the Sonos community. I appreciate you for bringing this concern to us. I'd be happy to help you all here if you can send us screenshots where you set the timer and unable to change to a different tone for us to check.

When you set the timer in the Sonos app, you can do it in 2 ways.

iOS or Android:
1. Touch the Info & Options area on the Now Playing screen, and then touch Sleep Timer.
2. Select a sleep timer duration.

Mac or PC:
1. Click Sleep Timer from the bottom of the Select a Music Source pane on the right side of the Sonos app.
2. Select the desired time frame.

Note: The remaining sleep timer duration appears next to the Sleep Timer option.

If you have any questions about this, please let us know. We and the community are always here to help.

So maybe i am doing this all wrong then. When i go to my alexa app and device I can enter timer settings. Am i not in the correct place and do i need to do this from the sonos app instead??  If so its making sense now. 
 

how do i access in the sonos app

Why is the Sonos team writing about a sleep timer? A sleep timer is a timer that stops playback after a certain amount of time and the timer itself plays no sound.

The OP is clearly referring to an Alexa timer here, not a sleep timer and not a Sonos timer. 

The OP said he/she tried to change the timer sound in the Alexa app for the Sonos One, which didn’t work.

The timer sound cannot be changed for Alexa, this is not a Sonos limitation. You should however be able to change the sound of alarms by opening the Alexa app, navigating to Devices > Echo & Alexa > select your Sonos One > Sounds.

I can’t imagine timers and alarms set using Alexa on Sonos being of any great use though, since there is no separate alarm/timer volume on Sonos for Alexa. Meaning that if you’ve been listening to music at 30% volume, the alarm/timer will sound at that same volume. Which is dumb.

This problem was first brought up in this forum 3 years ago, by the way: https://en.community.sonos.com/amazon-alexa-and-sonos-229102/sonos-one-alexa-alarm-volume-6793531

And people are still complaining: https://en.community.sonos.com/amazon-alexa-and-sonos-229102/is-there-a-way-to-increase-the-timer-volume-when-set-by-alexa-on-sonos-one-it-s-way-too-quiet-6850053

The feature itself has been present on Echo devices since 2016 and Sonos hasn’t managed to do so 4 years later.

The same limitation applies to Google Assistant on Sonos as well.

I use the timer almost every day. I do powdercoating and constantly set timers so I dont  overbake. If people are still complaing about it then maybe it needs fixed. I didnt post this to get lectured on why timers are dumb. For some of usit is very useful and it would be nice to change to a louder tone other than the default tone

I totally agree. Timers are a very important thing to me as well, which is why I’m so frustrated with the fact that there’s no separate timer/alarm volume for Alexa/Google Assistant on Sonos speakers. The issue I mentioned above might well be one of the reasons why you were looking to change the timer sound.

I actually dont want to change the sound. I want to change the tone from the default tone.