According to online reports, Apple has introduced in two new bit-rate options into iTunes 10.6 for users who sync their iTunes library to their iPhone or iPad.
Most audio tracks are encoded at 256 kbps if they are purchased from the iTunes Store. Now you can keep that quality when you send your files to your iOS device.
Starting with iTunes 10.6, users will be choose to sync their tracks at 256 kbps, 192 kbps or 128 kbps. This new setting will give users the flexibility to select the right encoding to match the storage of their device and their preferred audio quality.
Music lovers with a 64 GB device would not have to sacrifice audio quality. Those with lesser space like 16 GB of space can choose to sync a smaller, lower bit-rate file.