Love cheats or lazy employees looking for a "sound alibi" may have found a handy one, quite literally.
The new technology will work on selected Nokia phones
A German company has come up with a mobile phone accessory which can play background noises during a call.
Users have a choice of nine sounds - they can pretend to be in a traffic jam, a dentist's surgery, a circus parade or a thunderstorm.
The firm, Simeda, admits the morality of the system is a bit dubious but insists it is "just a bit of fun".
Advertising for the Soundcover system on Simeda's website spells out the new alternatives to conventional methods such as putting on a croaky voice or blowing down the receiver whispering "You're breaking up".
"Did you wake up late for work and you want your boss to think you're caught in traffic?" it says.
"Select the Traffic Jam background and give him a call from your bedroom."
The selection includes a phone ringing 15 seconds into a conversation - so you can get rid of an unwanted caller by telling them you are wanted on the other line.
"We were thinking about the future of background photographs and this idea came up," Simeda's chief executive Liviu Tofan said.
He added there had been "an incredible buzz" since the accessory went on sale a few days ago.
Jason Jenkins, deputy editor of the leading gadget and technology magazine T3, warns it may well stifle individual creativity.
At the dentist
On the street
In the park
Ring 15 seconds
Own pre-recorded sound
"If you need to make a call to your boss or girlfriend then you should get a friend to make some noise in the background, or stick your head out of the window to pretend you're in a traffic jam," he said.
Other experts warn some people on the other end of the line will never be fooled, no matter how elaborate the scam.
"It is dishonest to disguise your voice or where your are," Richard Wright, professor of linguistics at Washington University says.
"But if a husband used the system to lie to his wife about where he was, she would probably be able to tell from his voice that he was lying."
Initially the product will work on selected Nokia phones.
The company says it will soon be available for most makes.