voice memo m4a to wav

Hi
I wish to convert the m4a voice memo files to wav so that I can attach the voice files to the gps track when editing the Open Street Map using the JOSM editor. To do this the time stamp needs to be maintained so that the recording can be aligned with the correct part of the gps track. All the conversion programs I have tried change the time stamp to the time they are modified. Any method? The voice memos app on my iphone 4 works well as it syncs the files to my Imac for easy upload to JOSM but unfortunately records only in m4a.
I have tried other apps that record in wav but to get them on to the Imac sometimes involves sending each sound file individually by email or sending to the cloud and then when retrieving from the cloud the timestamps are changed. On a gps track on my cycle I may record hundreds of individuals sound files.
Initially I thought I would try to convert the m4a files as the syncing makes it easy and quality is fine. A unix or perl script would be great. Or is there a voice memo app that produces wav that can be synced easily so I can upload the files easily.

Would be nice to know what Apps/program's you have tried so we are not going on a wild goose chase
As well as what model Mac and what OS you are running is always a good thing so we don't recommend something that isn't compatible with your Mac.

The first one I would suggest anyway is Audacity. Here is some help on importing them to iTunes or Mac if needed ......... How to import files from iTunes - Audacity Wiki

If you need more help there is a lot of help at Audacity Wiki

Oh and welcome to the forums

Here's a free program that can do what you want: MediaHuman Audio Converter - free audio converter for Mac OS X and Windows

Not aware of "any" app that creates files that is going to over ride the operating system's function of "time stamping" a file at the time of it's creation.

bobtomay said:

Not aware of "any" app that creates files that is going to over ride the operating system's function of "time stamping" a file at the time of it's creation.

Click to expand...

Good point. Never really dawned on me last night that that time stamping by the OS might be an issue.

Hi
thanks for replies.
I found a good app with big buttons to use for recording the voice waypoints whilst cycling - mVoice.
It saves wav files and sends them to the cloud when wifi available.
The iPhone sits in my old Garmin leather case strapped onto the handle bar.
I have my gps recording app running in the background - there are zillions of these - I use MotionXgps. I have the mVoice app running and just have to speak each waypoint as required by pressing the "Record Start" and "Stop" buttons on the screen as I ride on. A bluetooth mic would be good to try but all seems ok without it as I just lean over a bit to speak but seems to attract curious looks when near pedestrians.
When I get home, as soon as the files have gone into the cloud, I go to the cloud web site and select and download as a zip file the files I recorded.
After unzipping I find that the time stamps have been all changed to the same time.
The mVoice app saves the situation by using the time of recording as a filename.
eg 20130506105631.wav
I wrote a small shell script to use the filename to change the "modified timestamp" back to when the recording was made.
When using the JOSM editor for editing the Open Street Map, I can upload the gpx track and then upload the sound files and they are placed along the track using the timestamps, making editing street names, etc quite easy to do.

The small shell script is below if curious...

#!/bin/bash
echo "The script starts now"
cd /Users/me/Documents/JOSM/Gps_voice/mVoice

for i in $(find *.wav) ; do
touch -t $(echo $i | sed 's/\([0-9]\{12\}\)\([0-9]\{2\}\).wav/\1.\2/') $i;
done

There are probably apps available that would do the job better but this works fine for me for now.

The app ClearRecord links to ITunes and allows the wav files to be copied to the IMac , preserving the timestamps too, but I find it a bit hard to operate the buttons in this app on the iPhone to make the sound recordings whilst on the move.

Thanks chas_m - I'll check out that app. I am using "Switch" - NCH software to convert m4a to wav but there is no option to conserve the ordinal timestamps.

Best wishes and thanks for you input.

edit…
It is probably correct etiquette to include the links mentioned so here they are...
mVoice Rec By Mikikimedia
https://itunes.apple.com/au/app/mvoice-rec/id545249736?mt=8
MotionX-GPS
MotionX® | MotionX-GPS Overview
ClearRecord (Lite version)
Ittiam | Content Pages | ClearRecord - Noise Free Recorder with Play Speed Control
Switch Audio File Converter Software
Audio Sound File Converter Software. Convert wav mp3 dvd midi flac dvf wma etc.
OpenStreetMap
OpenStreetMap