I've searched supported format audio files but I've found below formats only. 

```
kAudioFormatLinearPCM               = 'lpcm',
kAudioFormatAC3                     = 'ac-3',
kAudioFormat60958AC3                = 'cac3',
kAudioFormatAppleIMA4               = 'ima4',
kAudioFormatMPEG4AAC                = 'aac ',
kAudioFormatMPEG4CELP               = 'celp',
kAudioFormatMPEG4HVXC               = 'hvxc',
kAudioFormatMPEG4TwinVQ             = 'twvq',
kAudioFormatMACE3                   = 'MAC3',
kAudioFormatMACE6                   = 'MAC6',
kAudioFormatULaw                    = 'ulaw',
kAudioFormatALaw                    = 'alaw',
kAudioFormatQDesign                 = 'QDMC',
kAudioFormatQDesign2                = 'QDM2',
kAudioFormatQUALCOMM                = 'Qclp',
kAudioFormatMPEGLayer1              = '.mp1',
kAudioFormatMPEGLayer2              = '.mp2',
kAudioFormatMPEGLayer3              = '.mp3',
kAudioFormatTimeCode                = 'time',
kAudioFormatMIDIStream              = 'midi',
kAudioFormatParameterValueStream    = 'apvs',
kAudioFormatAppleLossless           = 'alac',
kAudioFormatMPEG4AAC_HE             = 'aach',
kAudioFormatMPEG4AAC_LD             = 'aacl',
kAudioFormatMPEG4AAC_ELD            = 'aace',
kAudioFormatMPEG4AAC_ELD_SBR        = 'aacf',
kAudioFormatMPEG4AAC_ELD_V2         = 'aacg',    
kAudioFormatMPEG4AAC_HE_V2          = 'aacp',
kAudioFormatMPEG4AAC_Spatial        = 'aacs',
kAudioFormatAMR                     = 'samr',
kAudioFormatAudible                 = 'AUDB',
kAudioFormatiLBC                    = 'ilbc',
kAudioFormatDVIIntelIMA             = 0x6D730011,
kAudioFormatMicrosoftGSM            = 0x6D730031,
kAudioFormatAES3                    = 'aes3'

```

I want to record audio file in format of **speex**, because It's just enough to record speech. Is it possible with `core audio framework`? 

**Ref:** I've found [this lib](http://code4app.net/ios/Speex-Audio-compress/52139e0a6803fa4503000000). But It is too complicating process. I want to use simple control with `AVAudioPlayer or AVAudioRecorder.`