Until now the examples used were strictly in English. This next set of six samples recordings are in six different languages; Norwegian, Chinese, French, German, Russian & Spanish. Each is presented in a comparative form, with three codecs intercut into one example recording. Then again in each of the following; uncompressed, super-wideband (G.722.1C), wideband (G.722/G.722.1) and finally narrowband (G.711) a la PSTN.
I could have assembled all of this into a tight little library using Flash or some Javascript, but I decided that it would be better presented laid out across a number of pages in a very plain and simple form. This way you know for certain exactly what you’re hearing and seeing in each case. There’s no active logic in the background except for a little MP3 player embedded in the page.
In order to truly appreciate the difference between the various recordings you will need to be making use of high-quality audio playback hardware. Good quality computer speakers or, better yet, a high-quality headset will be the most revealing. But then, as someone who’s genuinely concerned about the quality of audio over IP telephony…you knew that, right? I thought so.
Audio Sample #3: The Male Voice In Norwegian
The third sample in the set is the voice of VoIP blogger Ruben Olsen of Open-VoIP.com who contributed a sample in his native Norwegian.
Ruben Olsen, Norwegian comparative (G.711, G.722, uncompressed wave)
I regret that in going through my library of samples I was not able to find a G.722.1C encoded version of Ruben’s dialogue. Therefore in this one case I’ve used the uncompressed original in the comparative example. If I get the opportunity to recreate that one file I will try to so so just to have a truly consistent set of examples.
Ruben Olsen, Norwegian uncompressed wave
Audio Sample #4: The Male Voice In Chinese
The remaining voice samples were collected by Michael Iedema by recording various co-workers in the facility where he works. The first of these is a fellow speaking his native Chinese. I’m not sure what dialect, as I don’t speak Chinese myself.
Male voice, Chinese, comparative encoding, G.711, G.722 & G.722.1C
Male voice, Chinese, Uncompressed Wave File
Male voice, Chinese, G.722.1C encoded
Male voice, Chinese, G.722 encoded
Male voice, Chinese, G.711 encoded
Audio Sample #5: The Male Voice In French
This next voice sample is a male voice speaking French, but not Parisian French, nor even Quebecois. This gentleman speaks French as it would be found in The Republic of Cameroon, a west African nation that was at one time a French colony.
Male voice, French, comparative encoding, G.711, G.722 & G.722.1C
Male voice, French, uncompressed wave file
Audio Sample #6: The Male Voice In German
Sprechen ze Deutsche? No? Me neither, but evidently this fellow Christian does.
Male voice, German, comparative encoding, G.711, G.722 & G.722.1C
Male voice, German, uncompressed wave file
Audio Sample #7: The Male Voice In Russian
Male voice, Russian, comparative encoding, G.711, G.722 & G.722.1C
Male voice, Russian, uncompressed wave file
Audio Sample #8: The Male Voice In Spanish
Male voice, Spanish, comparative encoding, G.711, G.722 & G.722.1C
Male voice, Spanish, uncompressed wave file
In the fourth and final part in this series I’ll present some closing thoughts on the evolution of the role of codecs, and the merits of the various codecs presented in the samples.