There five factory-set audio profiles as follows:
•Portable hands free Low-level is recommended.
•Handset
Low-level is recommended.
•Car kit
Low-level is recommended.
•Speakerphone High-level is recommended.
•Headset
Low-level or High-level can be used with headset, depending on requirements.
Portable hands free is the factory-set default profile. The modification, configuration, manipulation and storage of audio profiles is achieved with the AT*E2EAMS (Audio Profile Modification) and AT*E2APR (Audio Profile).
5.9.1 Auxiliary Audio to Mobile Station (AUXI)
AUXI is a single-ended auxiliary analogue audio input to the wireless modem. Internally, the signal is routed to the CODEC (COder/DECoder), where it is converted to digital audio and mapped to an internal bus.
AUXI provides a DC bias when it is used as the microphone input in Portable Hands- free applications. All other sources must be AC-coupled to avoid attenuation of low frequencies, and to prevent incorrect biasing or damage to the AUXI input. Use a capacitor greater than the value shown in the table below.
The AUXI input is a passive network followed by the transmit part of the CODEC.
| Parameter | | | Conditions | | Min | | | Typ | | | Max | | | | Unit |
| | | | | | | | | | | | | | | | |
| Input voltage full scale | | | max input gain | | 142 | | | 158 | | | 178 | | | | mVrms |
| | | min input gain | | 447 | | | 501 | | | 564 | | | | mVrms |
| | | | | | | | |
| Frequency response | | | -3dB cut-off | | 300 | | | | | | 3400 | | | | Hz |
| Output dc bias level | | | | | 2.16 | | | 2.4 | | | 2.64 | | | | V |
| AC coupling capacitance | | | | 1 | | | | | | | | | | ∝F |
