The researchers questioned almost 2,000 people who had registered with the DMA's suppression file, the Telephone Preference Service, during May. They found that 98% of those questioned had signed up for the service to stop calls about products that were not relevant to them.
As many as 73% of people who registered receive fewer than one call a month, and 96% of respondents said they were satisfied with the service the TPS provides.
The service was said to be easy to sign up to by 99%. Around 37% of those questioned said they registered to put a stop to silent calls, while 55% wanted to stop calls at inconvenient times.
Tessa Kelly, head of the Telephone Preference Service at the DMA, said: "We acknowledge that some people do find this an intrusive way of being contacted by companies, so it is pleasing to know the mechanism we have put in place to help these consumers is working successfully.
"The DMA is committed to ensuring consumer trust and confidence in direct marketing, so this research shows how the safeguards in place can help."
The TPS is administered by the DMA and is sent to companies that have signed up to the service
The latest MORI research figures show awareness of the TPS is 33%. More than 3m consumers are registered with the service.
Consumers can register online or by calling 0845 070 0707.
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