DSP or ARM for wireless 2 way audio door phone

kevinchime2

This is a project for 2 way audio door phone, the features might be as listed below.
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7 L2 K$ F# n5 ?/ w1 y' }1. Battery operation, hence low standby consumption is important. The RF sniffing structure must be well organized, short wake up time, low standby current.
/ @/ o, K4 _' L* c2. 2 way audio ability, it means echo cancellation ability is necessary. The IC selected would need a DSP inside or any software base library to address the echo and howling problem.
& H- v. m0 K4 k# l* ]! u/ N5 j3. RF media is 2.4GHz with frequency hopping, the IC selected should have the SPI interface to do the communication.
4. The audio input will need an ADC to pick up the signal and with internal codec to compress the audio signal.
8 j8 b) e8 @. C: H5. For the audio output, the internal decode must be able to convert the signal into analog signal.
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5 W2 h$ a$ a- qIs there any recommendation for suitable IC for our applications?
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9 m) F$ f/ B, Y  nregards!