I have a client that requests that would like to know if<br>the following is possible:<br><br>(1) Introduce a one second pause between the system menu<br>prompts as they feel that the prompts can appear to be<br>"rushed" to the novice Unity user while retaining the<br>original system prompts and not having to re-record them. <br><br>(2) They would also like to slow down the system's reaction<br>to skipping the greeting (in our case '#') by a half of a second.<br><br>(3) They are concerned with static and hiss that follows<br>a system prompt waiting for user input. I believe that<br>this may simply be comfort noise. They would like to<br>reduce, or eliminate it.<br><br>--- Thanks ---<br><br>
Unity currently does not allow for special features on the end of prompts, like pauses.
We cannot do the pause before reacting to key presses either.
So I would be left with the option of taking
the main system prompts putting them into
a sound recorder app, and prepending a little
bit (1/3 of a second) of space into it?
Also, the minor hiss that occurs after a system
prompt as it awaits user input, is that comfort
noise, or something else? If it comfort noise,
is it Unity or CallManager generating it?
I find it very light in the background, but others
find it noticable.
--- Thanks ---
Then I am unsure where the "hiss" is coming from.
It is audible after the Unity prompt "wav" has finished
and is awaiting caller input and ends when another
What is Unity doing with the ports (TAPI integration
with CM 3.0.9) after it plays a prompt?
You can call and listen for the "hiss" at 847-874-2000
and listen carefully after the "press the pound key" at
the end of the main greeting prompt.
--- Thanks ---
I called in and heared what you are talking about. The only noise that Unity generates during a connected call is during the playback of a .wav file. That file might be a system prompt or in this case a custom recorded prompt.
Some of our system prompts actually have "silence" recorded for a bit after the prompt is spoken. At times that "silence" can be heared and interpreted as hiss, but this case is different. I assume that if you play that custom prompt back over a .wav player, the hiss is not recorded at the end of the message. Is that true?
After a prompt (custom or system) Unity does not generate any noise.
Is it possible that VAD and/or comfort-noise is enabled on the gateway?
The "gateway" in this particular install is via CM's
uOne ports, which do not have any real "tweak knobs"
The "hiss" seems to be present after the wav file for
the prompt plays - when the system is waiting for user
Silence Supression is currently set to F in both the
system wide and gateways service parameters on the
As far as the gateway questions that I asked, I was referring to the piece of equipment that connects the IP telephony network to the PSTN. Depending upon which type of gateway, that gateway does have some tweaking available.
Do they get the same "hiss" when the call is placed from an IP phone as opposed to an external phone?
It's likely that we'll have to punt this one to the CallManager folks. I called from one IP phone to another, and then hit the mute button (to simulate what it's like when Unity is not transmitting audio). I got a similar "hiss" (although not quite as loud as your site) after hitting the mute button.
If they call from one phone to another and hit the mute button, does the same "hiss" show up?
The hiss does appear to be the same one present when
muting a IP phone.
We have confirmed this issue on multiple sites now.
The problem does appear to be present on both CM3.08
Unity only seems to make the issue obvious when you
go from clean wav file prompt, to the hiss generated
apparently by CM.
I guess I am at a loss, because I though that CallManager
has nothing to do with the conversation once the stream
is set up between the IP Phones. . .
We understand that this is a VAD issue, as the service
parameters for this have been tried in both on and off
settings under the Call Managers.
Gain control or attenuation maybe?