Thousands of US webcasters will go silent on 26 June in a bid to draw attention to impending royalty rate increases that the industry believes will shutdown the country's internet radio.

Internet radio stations warned earlier this year that they could be forced off the air by a proposed increase in the royalties they pay to play music.

US copyright body the Copyright Royalty Board proposed in March to double the amount webcasters pay for every track they play.

"The arbitrary and drastic rate increases set by the Copyright Royalty Board on 2 March threaten the very livelihood of thousands of webcasters and their millions of listeners throughout the country," said Jake Ward, a spokesman for the SaveNetRadio coalition.

"The campaign to save internet radio, a grassroots movement comprised of hundreds of thousands of webcasters, artists, independent labels and listeners, has quickly brought this issue to the national forefront and the halls of Congress, but there is still more to be done before the deadline of 15 July.

"On Tuesday, thousands of webcasters will call on their millions of listeners to join the fight to save internet radio and contact their Congressional representatives to ask for their support of the Internet Radio Equality Act."

Ward said that many webcasters are planning to shut off access to their streams entirely, while others plan to replace the music with long periods of silence, static or "ocean sounds" interspersed with occasional brief public service announcements on the subject.