iPhone sales may be down in the next few months as consumers wait for the next model. Apple

Interest in buying a new iPhone is down again, according to a survey by Piper Jaffray.

Research analysts at Piper Jaffray last week polled just over 1,000 consumers in the United States asking about planned smartphone purchases for the upcoming three months. Only 34 percent of the respondents said they expect to buy an Apple iPhone in that period. That percentage is down from 39 percent in February, 44 percent in December, and 50 percent just after the iPhone 5s/5c launch.

A contributing factor to the drop is the impending iPhone 6 launch, rumored to happen in September. Interest in iPhone purchases traditionally wanes in the months prior to a rumored release, so the dip shouldn’t be seen as a turning point for iPhones, especially considering the next model is expected to be a completely new design.

The iPhone 6 is rumored to be much larger in design. Apple is said to be releasing two models of the iPhone 6, a 4.7-inch version and a 5.5-inch version, which would mark Apple's entry into the phablet market. That model, which some have called the iPhablet, is expected to release sometime in early 2015.

Other improvements for the iPhone 6 may include a collaboration with Beats Audio, which Apple is in talks to acquire. Beats by Dr. Dre is known for high-end headphones with boosted bass response. Depending on his percentage of ownership, Dr. Dre, born Andre Young, stands to become the first billionaire hip-hop artist in the world, despite not releasing an album of his own in 15 years.

This news comes just weeks before Apple’s annual developers conference, WWDC, where Apple will announce the next version of iOS and OSX. iOS 8 will give developers and other interested parties a glimpse at what's in store for consumers when the iWatch, iPhone 6 and iPad Air 2 are all said to be released around the same time this fall.