Once Jabber has permission to use your microphone: https://gcisdhelp.zendesk.com/hc/en-us/articles/360046489893-Jabber-Allowing-Cisco-Jabber-to-use-your-Macbook-Microphone
and after you try resetting Jabber: https://gcisdhelp.zendesk.com/hc/en-us/articles/360050001294-Jabber-Reset
If you can still not be heard or hear in some calls try the following steps (Macbooks may look slightly different but have very similar steps):
1. With Jabber open and signed in click on the little gear in the top right corner and click on "settings". (On Mac it will be located in the top left corner of your mac by the black apple and select "Preferences".)
2. Once in settings we are going to click on "Audio". (If on Macbook it should be "Audio and Video")
3. From hear we can adjust and test the volume of the microphone and speaker. To test your speaker click on the play button next to the drop down and it will play a dial tone through the selected speaker. (For Macbook it is a button that says "Test speaker")
The second bar below microphone should be changing as it picks up sound which will let us test your microphone.
4. If the bar for the microphone and/or the tone from the speaker don't work properly then select the drop downs and change the microphone and speaker for dell your devices should match the screenshots if you aren't using external speakers or a microphone. (For mac they should just be saying "Built in Output" and "Built in Microphone")
If these are not options or no options that register properly show up please submit a help ticket.
5. If these are all correct then at the bottom of the page we are going to select "Keep using the current Microphone or speaker" and hit "Apply". (On Macbook you do not need to "Apply")
Then attempt to test jabber in a phone call as this should fix the issue.