Long Distance Competition/Ultracycling, Randonneuring and Endurance Cycling - Anyone used audio cue sheets?

I'm doing a 400km event in a month and am thinking about making an mp3 audio file with all the cues in it to complement the map. The event will be partially at night, and will occasionally involve traversing urban areas (it's in Holland, which is densely populated).

I thought of recording all the cues into an mp3 file. Each cue would consist of the specific turn and also a sentence listing a landmark where the subsequent cue would occur. I could then turn off the mp3 player until the landmark arrives, turn on the mp3 player and get the next cue, etc.

This sounds like maybe a little bit of hassle for the countryside, but in the urban areas, I could just leave it on and the cues would be every minute or so. I also would avoid having to read the cue sheet at night.

I figured that audio cues plus a paper map would be easier to follow than reading a cue sheet and a map.

Ever tried this? Suggestions?

Maybe you're not like this, but I need to check cues more than just once before the landmark, especially when I'm tired. On a long stretch, I reassure myself repeatedly that I'm on the right track.

I guess this could work for me if there were a way of repeating the cues, such as using audiobook chapter markers, but if I double-triggered one and ended up in the wrong place, or lost power and reset to the beginning, it would be a big pain to find the right marker again.

I read the cues over and over myself, particularly if there was a hill that throws my sense of how fast I should reach the next cue. I did have trouble in the 400k I just did, because it started raining at night, we were on twisty, hilly roads, my glasses were wet, and I needed my helmet light to see. If it hadn't been raining and foggy, the paper would have been best. I suppose you could back up and listen again, but most mp3 players would be done with the ride after 5 minutes.

I'm really considering gps, because under the conditions I did this ride, paper was very difficult to handle.

I print my cue sheets a few days before the event, and map the route on a site like Veloroutes or Bikely.
I also use a highlighter and line every other instruction, sometimes using a 2nd colour every 10th turn, to make it easy for my eyes to find the right spot on the cue sheet.

I'll probably just use audio for the urban parts of the ride.

I was planning on laminating the paper cue sheet anyway. I have a plastic map holder on my handlebar bag, but rain can still creep in. You never know when it will rain in Holland.

I wasn't sure if there are GPS units you could carry on a bike with audio output, I assume there are. But I'm not going to spend that much money on GPS. I still prefer paper maps.

I'm not sure whether I will be relying primarily on my cue sheet or my map. Holland is tricky, with all those cyclepaths that don't always show up on google, it's hard to tell sometimes whether it's a shortcut or not. I have some good paper maps of Holland too showing cycle routes but it is still a bit of a guessing game.

This will be my second 400k race. Might even make a habit out of it.

I was reading some other threads and liked the suggestions for making cue sheets more readable; arrows instead of words, alternating colors, etc.

Thanks for the suggestions.

I read the cues over and over myself, particularly if there was a hill that throws my sense of how fast I should reach the next cue. I did have trouble in the 400k I just did, because it started raining at night, we were on twisty, hilly roads, my glasses were wet, and I needed my helmet light to see. If it hadn't been raining and foggy, the paper would have been best. I suppose you could back up and listen again, but most mp3 players would be done with the ride after 5 minutes.

I'm really considering gps, because under the conditions I did this ride, paper was very difficult to handle.

Similar conditions are what induced me to buy a GPS in the first place. On BMB 2006, there's no possible way I could have finished in time without the GPS -- deluge of rain, nightime, third night, 40 miles to the control with 4 hours to do it in and at least two major climbs. Any cue-sheet reading error would have been fatal. But the GPS told me exactly the correct route and all I had to do was follow it and ride like hell and sing to myself to stay awake.

Nick