PreferenceSpecifiers Title Codecs Type PSGroupSpecifier DefaultValue Key speex_16k_preference Title Speex 16Khz Type PSToggleSwitchSpecifier DefaultValue Key speex_8k_preference Title Speex 8Khz Type PSToggleSwitchSpecifier DefaultValue Key silk_24k_preference Title Silk 24Khz Type PSToggleSwitchSpecifier DefaultValue Key silk_16k_preference Title Silk 16Khz Type PSToggleSwitchSpecifier DefaultValue Key amr_preference Title AMR Type PSToggleSwitchSpecifier DefaultValue Key g722_preference Title G722 Type PSToggleSwitchSpecifier DefaultValue Key g729_preference Title G729 Type PSToggleSwitchSpecifier DefaultValue Key gsm_preference Title GSM Type PSToggleSwitchSpecifier DefaultValue Key ilbc_preference Title ILBC Type PSToggleSwitchSpecifier DefaultValue Key pcmu_preference Title PCMU Type PSToggleSwitchSpecifier DefaultValue Key pcma_preference Title PCMA Type PSToggleSwitchSpecifier