Cisco Unity volume level problems

[TCC_2]

Core Issue

Volume gain, which results in an increase or decrease in volume, can be distorted through these devices:

• IP phones—there is no configurable gain.
• Analog gateways—the gain can increase or decrease.
• Digital Signal Processors (DSPs)—the gain can increase or decrease.
• Cisco Unity Telephone Application Programmable Interface (TAPI) Service Provider (TSP)—either on-board Cisco Unity Automatic Gain Control (AGC) through a Dialogic TSP or playback and record gain values in the Cisco Unity TSP registry can be modified.
• Cisco Unity AGC—the volume can be increased and decreased through the AGC.
• Public Switched Telephone Network (PSTN) devices—volume is usually not altered and the process by which it can be is unknown.

Resolution

These are the Cisco Unity audio problems experienced:

• Low volume level
• High volume level
• Volume levels that fluctuate

Low volume levels are the most common problem experienced, while volume levels that fluctuate can also be perceived and reported as garbled voice.

Note: Be aware that multiple sources usually contribute to audio volume problems. These issues can occur at any point in a network, from a cell phone on an external call to the IP phone that receives a message from that caller.

In order to resolve the Cisco Unity volume problem, complete these steps:

1. Identify whether only Cisco Unity is affected by the volume problems.

   These are the main cases and actions related to this issue:

   • If Cisco Unity and phone-to-phone volumes are low, first check gain settings on the gateways in the environment, particularly if messages from only callers outside of the VoIP deployment are affected.
     
     
   • If only Cisco Unity audio volumes are low, run Regedit, browse to HKEY_LOCAL_MACHINE\SOFTWARE\Cisco Systems, Inc.\Cisco TSP and confirm this information:
     
     
     • WaveDBGainPlayback is 0, unless otherwise needed.
       
       
     • WaveDBGainRecord is 0, unless otherwise needed.

   Notes:

   • When these values are checked, keep in mind that they offset each other.
     
     
   • While other devices in the deployment can also control gain levels, it is easiest to disable settings on gateways that deliver audio to Cisco Unity. This quickly isolates a volume issue.
     
     
   • Cisco Unity versions later than 3.1(2) have AGC available.
     
     
   • If AGC is enabled, the target message recording level is 26 decibels, by default.
     
     
   • If AGC is enabled, the WaveDBGainPlayback and WaveDBGainRecord values must always be 0.
     
     
2. Identify the particular Cisco Unity functions affected by the volume problems.

   These are the main cases and actions related to this issue:

   • Cisco Unity-Legacy PBX integrations are present. Refer to Cisco Unity-Legacy PBX Integration: Adjusting the Volume in Registry for more information.
     
     
   • All messages are affected except for the Cisco Unity system prompts. These are at an acceptable level. For Cisco Unity version 3.1(2) or later, AGC default settings must be checked. Refer to these documents for more information:
     
     
     • Audio Quality
       
       
     • Reducing Noise in Recorded Message on Cisco Unity 3.1.2 or 3.1.3
       
       
   • If the Cisco Unity version is 3.1(2) or earlier, prompts or TSP gain levels must be checked. Refer to Audio Decision Tree for Cisco Unity 2.46 and 3.0x for more information.
     
     
   • If only some messages are affected, verify that the phone load is deployed for Cisco bug ID CSCdy27331.
     
     
   • If the voice message volumes are erratic, check the registry setting values for AGC as documented by Cisco bug ID CSCdw45310.
     
     
   • Only some subscribers are affected by different volume levels on phone and computer playback. Refer to Cisco Unity ViewMail for Outlook (VMO) Audio Volume Settings for more information.

Refer to these documents for more information:

• The Volume Levels and Gain Control section of Troubleshooting Cisco Unity Audio Quality

• Voicemail messages have a lower playback volume than Cisco Unity system prompts.

CallManager Versions

CallManager 3.x

Unity Version

Unity 4.x, Unity 3.x