Sound Communication: The Holdcom Blog

FAQ: Message on Hold Volume Control

This is the first installment of an ongoing series of “frequently asked questions." The full compilation of questions can be accessed from the menu bar on the home page.

Many of our clients, when previewing their Message on Hold programs through computer speakers, wonder why the background music sounds softer when compared to the vocals.

The background music is mixed low to compensate for the detrimental effects of playing a large frequency file over a system with low dynamic range [phone line]. In other words, the frequency spectrum of the background music contains more "highs and lows" than the human voice. If the non-compressed studio-mixed message on hold was played over a phone line, the phone system would not be able to reproduce the full range of audio data, and distortion would result. Therefore, we compress the file.

In order to re-capture the quality, phone systems use a process called companding that expands the compressed files, ultimately increasing dynamic range. We mix the music at a lower dynamic level before compressing, to compensate for the effects of companding the signal.  Otherwise the music would drown out the vocals.

Since our messages on hold are optimized for telephony, computer speakers are not the best way to monitor your program; call your phone line! It is important to regularly check your message on hold program via telephone, not only to insure that all announcements are functioning properly, but also to go through the “caller experience.” You can then adjust your program to provide the most informative, efficient, and enjoyable customer service.

Tags: message on hold