Viewers' complaints about the use of autotune on The X Factor have not been upheld by the broadcasting watchdog.
Ofcom was contacted by 45 viewers about technology being used to improve the quality of some performances on the hit ITV show.
Fans accused producers of using autotune - seen in studios to improve performances by correcting pitch and disguising off-key mistakes - to make some contestants' voices sound better.
Many of the allegations surrounded Gamu Nhengu, who was later immersed in another controversy when she was not put through to the finals by mentor Cheryl Cole.
Ofcom said that for it to investigate it would have to look at whether viewers were "materially misled".
That would have meant viewers were spending their money to vote on the basis of autotuned performances.
An Ofcom spokesman said: "There is no risk that viewers could have been materially misled.
"At that stage of the series the audience played no part in determining who is taken to the next round and no public voting was involved.
"But had viewers been paying to vote for some contestants that were autotuned, against others that were not, there may have been the potential for viewers to have been materially misled.
"However, ITV has confirmed that autotune has never been used during public voting on The X Factor."
An X Factor spokesman said in August that post-production work was necessary due to the number of microphones used during filming.
"The judges make their decisions at the auditions stage based on what they hear on the day, live in the arena," he said.
"The footage and sound is then edited and dubbed into a finished programme, to deliver the most entertaining experience possible for viewers."
ITV Director of Television Peter Fincham said in the summer that the show had used sound filtering technology but that it did not unfairly reflect any performance.Reuse content