The fifth instalment of the new BBC One reality series, which saw 9 nine acts make the live shows, was watched by an average of 9.9 million viewers, well down on last week's series high of 10.7 million.
For the first week since their launches last month, Britain's Got Talent and The Voice didn't clash, but it didn't help either show.
Britain's Got Talent 2012 was seen by an average audience of 9.7 million, including those watching on ITV1+1. The Simon Cowell series also experienced a week-on-week dip, falling from last week's 10.2 million figure.
In terms of peaks, The Voice won, with a top audience of 11.6 million watching the show at one point, the highest rating of the day.
Britain's Got Talent also peaked well, with 11.1 million viewers.
The figures are sure to be a disappointment for both the BBC and ITV, with no clash and longer run times, declining ratings weren't expected.
The Voice UK continues tonight and will continue to air on Sundays and Saturdays as the live shows kick off next weekend.
Britain's Got Talent meanwhile will kick off its live shows on Sunday, May 6.