MOH sounds fuzzy/lispy after MOH translation

Unanswered Question
May 15th, 2007

I'm using CM 3.3.4 (I KNOW!) and having an issue with MOH. I take a good .wav file, drop it in the translation folder, create new MOH source and update devices. Off and On Net Callers hear the recording but it sounds fuzzy and a lisp is heard with S words. I've checked the file before translation and it's perfect. MOH codec is G.711. I tried using G.729 but that made off net sound even worse. Any suggestions? I've checked with our vendor and have received "it should be working fine".


Thank you for your time.

~ Liz

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Overall Rating: 5 (4 ratings)
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gogasca Tue, 05/15/2007 - 08:31

Hi Liz,

We have opened a Sev 6. (enhancement bug) to use a new tool available and incorporate

this feature in the future release of call manager. The BUG ID is

CSCdy17968


The MOH Audio Translator service uses Microsoft DirectX (DirectSound) to

convert original files into 8kHz PCM data streams. This processing generally

works but the audio quality is not sufficient for some customers.


CCM's MOH converter is not designed to handle high quality music conversion while at the same time, still maintaining high quality audio fidelity.


The best recommended method is to record the audio with the parameters - 16-bit PCM

sampled at 16 KHz.


Most standard wav and mp3 files serve as valid input audio source files.

You can refer the following link :-


http://www.cisco.com/univercd/cc/td/doc/product/voice/c_callmg/3_3/sys_ad/3_3_3/ccmfeat/fsmoh.htm#1027445


That is not its main purpose. Again, its sole purpose is to convert a given wav and/or mp3 into different codec formats to be used over a VOIP network. If the original wav/mp3 file is also equalized or adjusted to lower the high treble bands (not too much), that will help decrease the extra "hissing" or scratchy sound, as you put it, after file conversion.


It is apparent that CCM's MOH Audio Translator will enhance these sounds in, for example, female lyrics/vocals, and or when a soprano type person vocalizes any given word/s. To add to that, there will be an enhanced hissing sound in the background as well. It may seem more magnified, then the original wav/mp3. That is what happens when a high quality, digital music recording gets converted to a lesser quality format.


On offline basis, because there are different types of file formats and different types of voice quality, per file, it is advisable to convert the same MOH file over again and again using different format structures, in order to see what works and what doesn't work for better MOH quality and audio fidelity.

This is where the trial-and-error approach comes in.


....

gogasca Tue, 05/15/2007 - 08:32

[Part 2]


Here is the manual MOH file conversion procedure (be sure you have a backup of the

original WAV file):

Which you can Forward to a Recording Studio


1. Convert the original WAV file using the MOH Audio Translator

2. Start CoolEdit and open the original WAV file

3. Edit --> Convert Sample Type

4. Set Sample Rate to 8000 and Resolution to 16-bit

5. Click OK

6. Transform --> Amplitude --> Amplify

7. Set Amplification to 40% (this can be adjusted but the normal recording is too high in

volume for MOH)

8. Click OK. You can play and UNDO (edit) until you are satisfied with the sound

9. File --> Save As

10. Change filename extension to ".ULAW.WAV"

11. Select "Save As Type:" to "A/Mu-Law Wave (*.wav)"

12. Click on Options button and select "MU-Law 8-bit" & click OK

13. Click on Save and answer Yes to overwrite if asked

14. File --> Save As

15. Change filename extension to ".ALAW.WAV"

16. Click on Options button and select "A-Law 8-bit"

17. Click on save and answer Yes to overwrite if asked

18. File --> Close

19. File --> Open (open the original WAV file)

20. Edit --> Convert Sample Type

21. Set Sample Rate to 16000 and Resolution to 16-bit

22. Click OK

23. Transform --> Amplitude --> Amplify

24. Set Amplification to 40%

25. Click on OK

26. File --> Save As

27. Change filename extension to ".WB.WAV"

28. Make sure "Save as Type:" is set to "Windows PCM (*.wav)"

29. Click on OK

30. Exit

31. Put the ".ALAW.WAV", ".ULAW.WAV" and ".WB.WAV" files in C:\Program

Files\Cisco\TFTPPath\MOH

directory to replace those created by the MOH Audio Translator Service

32. When done, there should be 6 files in the TFTPPath\MOH directory that have the same

base name as

the original WAV file:

a. Original.WAV

b. Original.xml

c. Original.ALAW.WAV

d. Original.g729

e. Original.ULAW.WAV

f. Original.WB.WAV


I was able to find: NHC Switch Sound

"NHC Switch Sound (its freeware) in order to change the encoder settings. You have to

notice that this program is not supported by Cisco and Cisco do not recommend any audio

program. I use it in order to find a way to help you. I tried several audio translator and I found it useful for our purpose. Feel free to use any software you want.

For NCH :

Format: PCM

Attributies: 8.000Khz, 8 bit, mono 7Kb/sec

http://www.nch.com.au/switch/plus.html


HTH

Let us know

egrinkin1 Tue, 05/15/2007 - 09:10

I will let you know as soon I can. Thank you so much for the detailed explaination and researching a solution.


More later,

~Liz

egrinkin1 Tue, 10/09/2007 - 11:42

After many attempts following the recommendation here, the MOH was still too poor to use. A new professional recording was done by a man with a very deep voice. 16khz/16 bit was lispy, but the recording in 8 khz / 8 bit has no lisping or hissing at all. The background music still sounds a little tinny, but it is acceptable.

Thank you for your continued support.

~ Liz

Rob Huffman Tue, 05/15/2007 - 13:26

Hi Gonz,


Really a fine answer here! You get my 5 point vote for sure :)


Thanks so much,

Rob

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