Hello, just an update to say ... I got no feeback / news from HikVision.
Not even a confirmation / acknowledgment for the the issue I reported through their form.
It now makes 4 units with this issue. I am not able to say if the issue was already there with the builtin firmware as, just like @gega I upgraded the firmware to the latest upfront as I was experiencing the same exact buzzing noise when touching the screen (press key sound artefact ...) which gave my upfront a feeling on poor quality. The firmware upgrade corrected the buzzing sound (no entirely but better). But not the microphone issue.
Not even a confirmation / acknowledgment for the the issue I reported through their form.
It now makes 4 units with this issue. I am not able to say if the issue was already there with the builtin firmware as, just like @gega I upgraded the firmware to the latest upfront as I was experiencing the same exact buzzing noise when touching the screen (press key sound artefact ...) which gave my upfront a feeling on poor quality. The firmware upgrade corrected the buzzing sound (no entirely but better). But not the microphone issue.