PCM2912A: Turn off Mic signal in speaker out...

Hi, Peter,

This part features a Mic mute option by sending a logic HIGH signal to MMUTE pin. However, this option mutes the input mic, not the speaker output playing the audio signal from the mic.

Could you please clarify if the speaker that plays the mic content is in the host system?, it is possible that the Listen to this device option is enabled by the computer in the PCM2912A from the recording devices window.

Best Regards,

  -Diego Meléndez López
   Audio Applications Engineer

Hi Diego,

Below are some testing by customer.

1. while mute enable, the Mic signal will stop to output to USB, however, the internal route to spk still have output

2. under WINXP, if not run record program, the Mic sound will not be gear in PC output.(assign output with another sound card), but there is output from PCM2912A

3. Under WIN7, same situation with WINXP, assign output with another sound card, it needs to check "listen to this device" to make it output.

Meanwhile, PCM2912A always has output even check or uncheck this setting

4. it seems PCM2912A still always output its Mic signal.

Please help to check it.

Thanks.

Dear Diego,

Simply speaking, what customer need is: Mic input from PC2912A and direct input to system without route to PCM2912A headphone out!
And system playback output to PCM2912A headphone only.
Is there any method to do that since now, even system nute is enable, the PCM2912A headphone will hear its Mic input sound.

Hi, Peter,

Thanks for the additional information. The device should not playback the content from the mic recording, it is not a normal behavior.  What customer is requiring is exactly the normal behavior of the device. I have tried my EVM and was able to verify this behavior. The only way to send the mic content to the headphone output is by checking the Listen to this device option.  

Best Regards,

  -Diego Meléndez López
   Audio Applications Engineer

Hi Diego,

Let me clarify the request from customer.

What customer need is, while Mic input from PCM2912A, they do not want to hear the Mic input from PCM2912A headphone output. 

Actually, it seems PCM2912A will loopback the EVM mic input to EVM headphone output at any time unless you disable PCM2912A. 

Hi Diego,

Thanks for your reply!

Below pic is my test device and configuration.

As you can see, the "listen to this device" did not check, but I can hear the mic voice from PCM2912A headphone, not NB headphone.

That is what customer did not want to hear.

You can take it try with my way.

Is there any way to turn off the mic loop back to PCM2912A headphone output?

Thanks.

Hi Diego,

After test, mute mic volume in level tab is not work for me!

I found it works if I mute mic in speaker tab.

However, customer system is not Win OS! he connected PCM2912A board via OTG cable into their system.

Is there any way to change any setting in such situation?

Thanks.