Cisco IP IVR wav file properties

[rockychaplin]

I have recorded prompts for the Cisco IP IVR in 8KHZ 8 bit u-Law format. Unfortunately this setting is very noisy. I have been recording (for our old IVR) in 44KHZ 16 bit PCM format. Can the Cisco IP IVR utilize 44KHZ 16 bit PCM format or is 8KHZ 8 bit u-Law the only format this device can use.

[jasyoung]

No matter what format your old or new IVR allows "on disk", you aren't going to get any better than 8KHz 8-bit uLaw quality, because that's the format used on the PSTN and it has to be converted at some point. IPCC Express supports choosing g.729 instead of g.711 prompts at install time, but those are the only two codecs and g.729 would be a reduction in voice quality.

That bitrate isn't that audibly ugly in and of itself. I've found that most tools (like Windows Sound Recorder) introduce a lot of imperfections in the recording when converting from higher bitrate format. I believe it uses the Windows builtin DirectShow filters, as does the CallManager MOH converter, which also does a lousy job converting high bitrate files. Look at Cool Edit (now Adobe Acrobat); we've found that it does a somewhat decent job.

Or, do your original recordings at the standard bitrate. This is the best way to get nice sounding prompts. Notice your average IP phone conversation sounds a lot better than most WAV file conversions; those phone conversations are also at the standard g.711 bitrate. We usually have all our IPCC Express prompts done with an IP phone.

[rockychaplin]

Thanks for your reply Jas. Recording with an IP phone might give me the highpass filter I need with the noise cancellation. I am currently using a Denon recorder and digitizing from tape.

Can you tell me how you record with an IP phone to create the wav file. We are not using IPCC Express so the IP IVR that we use requires me to upload the wav prompts.

[jasyoung]

Well, if it's the Cisco IP IVR product, that's got the same functionality as IPCC Express. What we like to do is use an IVR script to do the recordings. We call into its pilot number, it prompts us for a PIN, then it prompts us for a number, and then records a prompt. After confirmation, it drops it right in the prompt directory with a name like 'Prompt001.wav', or whatever number we give the script. We write all our IVR scripts to use those numbered prompt names, so we can do instantly effective prompt re-recordings just by calling into the recording IVR.

If you can't or don't want to do it that way, there's at least one other handy way. If you have access to a Cisco Unity voicemail system, its recording format is just right as well. If you have Unified Messaging, record a voicemail and pick the WAV file right out of the e-mail in your Inbox. If you have a voicemail-only installation, create an Internet subscriber account to leave messages for, to forward the voicemail WAV file somewhere you can pick it up. Or, record your prompt as one of a subscriber's greetings and you can pick them out of Unity's CommServer\Stream Files subdirectory.