Speaking of sound it is rumored that the iPhone 7 will come with headphones that connect via its Lightning port instead of the 3.5mm audio jack. This seems likely IF the rumors are true that Apple is ditching the trusty old 3.5mm jack on the iPhone 7.
Apple is also reportedly working on developing new wireless Beats headphones, according to 9to5Mac. In addition to new wireless headsets, 9to5 also says the company is developing a new Bluetooth in-ear headphone to be named "AirPods":
"Apple is prototyping a completely new set of Bluetooth earphones with the potential of launching the accessory alongside the iPhone 7 this fall. The new earphones are said to be completely wireless, which is to say that they do not even have a cable connecting the left and right ear pieces..."
"It’s expected that the in-development accessory will include a noise-cancelling microphone system, enabling phone calls and communication with Siri even without Apple’s prior in-line microphone and remote. In order to fit inside of the user’s ear, Apple will likely develop different sized ear sleeves for the hardware, similar to the approach used by Motorola and Bragi. Bragi’s headphones include a built-in button to answer calls, so Apple’s could have a control for managing calls and activating Siri.
"Apple has registered the “AirPods” trademark which may be what these are called. The headphones are planned to be a premium alternative to a new version of the EarPods, and are highly likely to be sold separately from the iPhone 7; a comparable model from Bragi will retail for $300."