Maximum Playback Level (dBm)

Parameter group

Trunk Interface

Access level

Field

Possible values

-21 through 0

Defaults

-15

Explanation

Specifies the maximum audio level that is played to a caller. The process Blueworx Voice Response uses to determine the volume at which a voice segment is played is as follows:

When a voice segment is stored in the database (see the Blueworx Voice Response for AIX: Designing and Managing State Table Applications information for details), Blueworx Voice Response determines the maximum signal level.
Just before a voice segment is played, Blueworx Voice Response calculates the difference between Maximum Playback Level and the maximum level that is in the segment.
When it plays it to a caller, Blueworx Voice Response attenuates or amplifies the whole voice segment by the calculated difference.

Here are two examples:

The maximum signal power in the voice segment is -18 dBm and Maximum Playback Level is set to -15 dBm. The difference is -15 - (-18) = +3dB. The whole voice segment is therefore amplified by 3 dB. Note that those parts of the segment that are less than -18 dBm are amplified by 3 dB, but are not increased to -15 dBm. For example, signals at -23 dBm are increased to -20 dBm.
The maximum signal power in the voice segment is -10 dBm and Maximum Playback Level is set to -15 dBm. The difference is -15 - (-10) = -5dB. The whole voice segment is therefore attenuated by 5 dB. For example, signals at -14 dBm are decreased to -19 dBm.

Therefore, the signal power level for a voice segment never exceeds the value that is specified by Maximum Playback Level. This technique also ensures that all voice segments are played at the same level regardless of the level at which they were recorded. Note, however, that because the same level adjustment applies to the entire segment and is based on the maximum signal level in the whole segment, a burst of loud voice (or other sound) in the segment can make the remainder of the segment sound quieter than expected.

Blueworx Voice Response continuously adjusts the gain of the connection, to prevent the level from exceeding this value. The value set for this parameter is the maximum transmit level that is allowed by the country telecommunications authority.