I don’t see problem to hear voice on mangoh board when voice call.
How about using at!avaudio to check if you can do audio playback first?
root@swi-mdm9x28-wp:~# microcom /dev/ttyAT
ati3
Manufacturer: Sierra Wireless, Incorporated
Model: WP7605
Revision: SWI9X07Y_02.28.03.05 000000 jenkins 2019/07/08 11:04:16
IMEI: 353532100020465
IMEI SV: 6
FSN: 2A917285070404
+GCAP: +CGSM
OK
at!avcfg=5,1,2
OK
AT!AVSETPROFILE=5
OK
AT!AVAUDIO=1,1,/home/root/0-to-9_8k.wav
OK
[ 1674.996800] afe_send_custom_topology_block: AFE SVC cal has invalid size: 0!
[ 1675.002968] afe_send_custom_topology: No cal sent for cal_index 7! ret -22
[ 1675.009736] afe_get_cal_topology_id: [AFE_TOPOLOGY_CAL] not initialized for this port 4096
[ 1675.039965] q6asm_callback: cmd = 0x10da1 returned error = 0x3
[ 1675.044876] q6asm_send_cal: DSP returned error[3] audio audstrm cal send
[ 1675.061278] adm_callback: cmd = 0x10328 returned error = 0x3
[ 1675.065998] send_adm_cal_block: DSP returned error[ADSP_EUNSUPPORTED]
[ 1681.114444] BUG: sleeping function called from invalid context at /usr/src/kernel/kernel/locking/mutex.c:97
[ 1681.123171] in_atomic(): 0, irqs_disabled(): 128, pid: 4105, name: aplay
at!avaudio=1,0
OK