When your company phone rings, that caller becomes a prospect. The brief time spent on hold, can be an extremely powerful marketing tool. - See more at: http://ilaudio.com/message-on-hold/#.VIyNuHtq3kY
On Hold Message 4 – Is there anything the caller should know about? This may be current news in your industry or seasonal promotion.

For those still using analogue or digital phone systems, voice on ISDN circuits has a bandwidth of around 4000Hz. The audio from an analogue phone is sampled at 8000Hz, and because of the nyquist theorem, must be low-pass filtered to 4000Hz. So any frequencies in the audio beyond 4000Hz are lost. Interestingly, the human ear and mind are good at recognising human speech, so this is considered "toll-quality" voice, i.e. good enough to pay for. This is the reason why certain vocalised letters are difficult or impossible to tell apart on the phone. For example, the differences between B, P, T, C, etc. are almost entirely above 4000Hz.
Helpful message on hold sections are meant to speedily improve the caller experience. Good content to provide during these sections might include information that the caller may be looking for on their call, information regarding access to a business location, troubleshooting steps and problem resolution and information on organizational changes that the caller may need before proceeding with their call.