Investigations by three Scottish trading standards authorities in Angus Council, East Dunbartonshire and East Renfrewshire revealed that the average UK household receives seven prank or unsolicited sales calls a month.
Some 78% of nuisance calls are made between 8am and 6pm Monday to Friday, when the general working population are out, so although they may not be deliberately targeted, elderly and vulnerable people are more likely to be at home.
The study found that as many as 40% of the calls received by elderly and vulnerable people are classed as nuisance calls.
Trading standards officers warn that since a ringing phone can cause a feeling of urgency, a rushing resident risks falling or tripping. Silent calls can leave people feeling frightened while those receiving the bulk of the calls are in turn more vulnerable to being scammed out of money.
Brian Smith, Trading Standards Institute's lead officer for Crime and Disorder and Senior Trading Standards Officer for Angus Council, said: "The impact of nuisance calls can be devastating. For many it is just an annoyance but for the elderly and the vulnerable, it can be dangerous."
Call blocking technology was found to stop up to 98% of nuisance calls, leaving residents in greater control of who contacts them.
Mr Smith said: "It is hoped that with a national consciousness of this type of problem combined with the successful call blocking technology, we could massively reduce the problem and ease the emotional and financial harm that some of the most vulnerable people in society face."