I’ve had a chance to test this today and with a basic test I couldn’t replicate the truncation issue on the iPhone 6 Simulator or an iPhone 5 running 6.1.3, iPhone tested with built-in mic and with the stock headphones. The audio files which were saved sounded like precise trims to the start and end of speech which I verified by opening them in a spectrum analyzer and making sure there were a few milliseconds of silence-level sound before the cut. For the headphones there was usually a little bit of padding. That doesn’t mean I don’t take the report seriously, just that it doesn’t seem to easily manifest with a 100% stock setup. I’d like to help get to the bottom of the issue you’re seeing.
Could I invite you to send me your app with which you’re seeing the issue so that I can run it on the same device here and hear what you’re hearing? You can send me a note via the contact form and I’ll respond with the email address you can send it to. Let me know if there is anything interesting about the environment you’re testing in; noise levels, anything special about the device, anything that comes to mind.
Just to get one possibility out of the way, something I remembered today while testing is that when I was first working on OpenEars I used to play back all of my test recordings in VLC, and I spent days trying to track down a truncation bug of about 200-500ms that was always present in playback even though the speech recognition appeared to be working on the words at the end of the utterance. Eventually I stumbled across this unhappy piece of info:
It is purportedly fixed but seems to regress now and then, so I consider Audacity or Fission to be reliable test platforms but VLC not. I wouldn’t trust iTunes because it is an app which has a few different ways in which it might attempt to interact with audio playback, but I haven’t had any issues personally with playing files directly in Quicktime X for checking playback. I’d also recommend only using the Xcode organizer to download your app file so you can get items out of the documents folder in your own filesystem:
* In Xcode, shift-command-2
* select “devices” up top
* select your device on the left
* under your device you’ll see “Applications”, select it
* See a window that allows you to select your test app
* hit “Download”
* go to your download location in your own filesystem
* right-click on the downloaded package
* select “Show Package Contents”
* open “AppData” and then “Documents”
For browsing a Simulator app documents folder, check out my tool for opening a simulator app folder here: