I have various simple short sound effects (damage sound, dying sound, thunderbolt, fanfare, breaking) for a game that is developed for Android currently.

I use OGG files: 96kbps VBR, 44.1KHz, 2 channels (that means stereo, right?).

I read the other stackexchange topics about "acceptable sound quality", but they're too general, address too many things. My experience is that even with 80kbps, my effects sound OK. But I tested it on a limited number of Android devices (including a Sony Ericsson Xperia Neo and a HTC Desire HD). My questions:

1. For mobile phones and tablets, generally, what parameters are recommended? Won't my 80kbps sounds be bad on a newer device (such as a modern tablet)?

2. I don't hear any difference between stereo and mono (2 channels vs. 1 channel, right?), is there any noticeable difference at all for mobile phones / tablets? (in terms of the player experience) May it worth it at all? I assume that stereo sounds take much more in memory (when they're decoded to PCM), despite of the fact that the compressed OGG size is practically the same.

Reacting to Roy T.'s great comment:

1. Actually, I couldn't measure the PCM size (Android decodes OGG internally), but I thought that stereo will take more space than mono when uncompressed

2. After throwing out one of the WAV channels in Audacity, and re-exporting it:

   • The new WAV file size is half than before
   • The OGG file size is practically the same as before

3. The sound effects and game music was recorded by my friend who is an experienced hobby musician/composer, but he knows little about computers & software so he just gave me some high-quality WAV files generated via his hardware.These were stereo, but if I check them in Audacity, both channels appear to be exactly the same.Can I consider them the same (=> moving to mono), or might there be some unnoticeable differences to the human eye?