Just ran a call test on the first customer unit returned to us.
Methodology: rang 9500 from landline, put landline mic on mute, held landline earpiece to right ear and listened to call quality while speaking into 9500.
Result: muffled voice quality on standard call setting, lacked volume and clarity and at times dropped out entirely.
Retested after changing call setting to Speaker mode: massive improvement in call volume and clarity, no dropouts.
Conclusion: either the ANC system on standard call setting is cannibalising sound, or the microphone for standard calls is dodgy, or the engineering settings for standard voice calls need adjusting.
REPEAT EXPERIMENT USING MY OWN 9500
Standard voice call setting found to be excellent.
HOWEVER: when switched to speaker mode on this second phone voice quality became appalling the exact reverse of customer problem.
Conclusion: ANC or settings?
How many microphones are on this device and do standard voice and speaker voice work through separate mics? If they work through the same mic then clearly microphone hardware is OK and this is a software/firmware problem.
I used Sound recorder to record an HD voice file, sounded great on both phones, if that helps in diagnosis.