VoIP management vendor Qovia is warning of what it regards as a nuisance waiting to happen: the inevitable arrival of audio spam that clogs VoIP customers' voice mailboxes.

VoIP spam, or Spit (spam over internet telephony), will rear its head as soon as there are enough VoIP customers to make it worthwhile for advertisers to send pre-recorded messages via IP, the company says.

"It's only a matter of time before the spammers see a critical mass," says Pierce Reid, Qovia's vice president of marketing.

In anticipation, Qovia has filed for a patent on software that detects voice messages sent in bulk or that are exactly the same length and then block them from being stored in voice-messaging systems. The company plans to start selling the software later this year.