The same goes with sales: You want your caller to be excited about talking to you.
our voice over artists. Snap Recordings has over 100 professional, industry-leading voice talents available. Pick a language, select a voice-over artist and click the play buttons to hear samples of their professional phone greetings, voice prompts and messages on hold. Voice Talent Player.

To write a comedy script well, you need to be open with yourself and your audience. Write about your flaws as a company, and present them in a humorous light. The easiest way to start is to write about forcing people to stay on hold and joke about it.
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.