What audio format should I use for Dictaphone iOS app?

I want to make a Dictaphone app for iOS and my preferred audio format is DSS, as I want the recorded file to be of small size.

Is the DSS format supported by iOS? If not, what other format can I use for my app?

DSS is not supported by iOS.

The audio technologies in iOS support the following audio formats:

• AAC
• Apple Lossless (ALAC)
• A-law
• IMA/ADPCM (IMA4)
• Linear PCM
• µ-law
• DVI/Intel IMA ADPCM
• Microsoft GSM 6.10
• AES3-2003

For information about each of the audio frameworks, see the corresponding entry in “Media Layer Frameworks.”