White Noise in IP Telephony due to crappy microphone inputs of sound chip? - Page 1
Forum section: electronics / general

author: nightfire
author_rank: Frequent Contributor
timestamp: May 02, 2023, 06:24:26 pm
content: Situation: @work we introduced a new telephony system, so that we have a virtual machine with the new PBX on-prem and users can/should do their telephony stuff via headset.We have some quality brands deployed, mostly bought in the Corona/Covid19 years, that were primarily used for Webmeetings like MS Teams, Zoom, Gotomeeting.In those environments, they performend fine.Now, after introduction of the new telephony system, we have the issue, that in some constellations a caller hears lots of white noise in the background. It is like the partner is standing in front of a waterfall.Depending on the setup, sometime it helps to reduce the microphone intensity, sometimes at the listeners end to reduce the overall loudness.After some tests, we determined that USB-based Headsets (USB plug, "soundcard" piece in the middle, and 3,5 mm jack at the other end to allow for a separatable headset) are rarely affected or at least way less affected than some pure 3,5mm systems that plug directly in the PC or notebook port.Some research showed that especially older (3+ years) systems with onboard sound chips were optimized for quality of output, so that some gamers could hear the enemy coming from far away, but inputs were in most cases neglected.An d it seems as the telephony solution we deployed has no real noise suppression, or we have not found some regulation of it yet...Headsets, where this really is obvious, include the Steelseriec Arctis 3, which has also hardware noisecancelling mics, and is considered a gret gaming headset from the audio quality.Anyone, who also could share some insight about quality of mainboard/notebook inputs for mics?

author: madires
author_rank: Super Contributor
timestamp: May 02, 2023, 08:00:25 pm
content: Or is it just comfort noise added by the VoIP phone system?

author: nightfire
author_rank: Frequent Contributor
timestamp: May 02, 2023, 08:37:47 pm
content: No. The phones exhibit some small amount of noise, that is barely audible, which I would count as comfort noise. We are talking here in some selective scenarios of a sound that is like you are on the phone with someone that stands with his mobile phone in front of some waterfall, or running car with hood open. Definetely not comfort noise. Those noise is about 10x louder than the comfort stuff I am willing to call "comfort".And, depending on some mic and speaker settings, the amount of noise changes a bit, what hints towards some kind of signal amplification that is influenced by that.

author: madires
author_rank: Super Contributor
timestamp: May 02, 2023, 09:01:03 pm
content: I see. Is there any difference in noise between laptops and desktops?

author: DimitriP
author_rank: Super Contributor
timestamp: May 02, 2023, 11:55:38 pm
content: QuoteOh boy! It sounds (!) like everything went wrong.Let me summarize:A) "we introduced a new telephony system"B) "after introduction of the new telephony system, we have the issue"If these are the same computers, with the same headsets that "performed fine" in the past, whatever you have going on now is with the "new telephony system".Find one of those machines with the extreme noise and call the person that made the decision on the "new telephony system" to ask them to open a ticket with the "new telephony system" support!The rest is speculation. ( or what will be known as the next 8 pages of this thread! )

author: coppice
author_rank: Super Contributor
timestamp: May 03, 2023, 12:29:22 am
content: Go back 15 or 20 years and the audio quality from motherboards, both input and output, could be pretty bad. These days its unusual to find something nasty, and when you do its usually a grounding problem causing hum, not white noise. Do you have AGC at work on the problem mic inputs? If the gain is being cranked up to some crazy extent, you might well hear some nasty noise when nobody is speaking. even with good hardware, but you will probably catch the gain being adjusted as someone starts to talk.An easy way to isolate a motherboard audio problem would be to try a USB audio adaptor with one of the problem computers. Even pretty cheap USB adaptors generally work quite well these days. If simply changing the audio device, and nothing else, fixes the problem with a headset its pretty certain you have truly nasty motherboard audio. I specifically said headset, as using a speaker and mic, and relying on echo cancellation, can do funky things with some audio adaptors. You might expect the mic and headphone/speaker sampling to be synchronised. You'd be wrong for most modern motherboard audio. To allow for SP/DIF synchronisation they broke the mic/speaker synchronisation some years ago. Modern PC echo cancellers try to work around that, but its not always successful.

author: nightfire
author_rank: Frequent Contributor
timestamp: May 03, 2023, 10:42:15 pm
content: Long story short, management decided to replace the headsets with 3,5mm jack with new models, that are also already used in this environment without big problems, after those symptoms could be reproduced in certain combinations and setups.So we will get some more USB-Headsets soon.For calliing the contractor: alreay did this, and the discussion boiled down to something like: If it works with a certain amount of your headsets, then our system works- please fix your end yourself...(Ok, they expressed it more politely)

author: DimitriP
author_rank: Super Contributor
timestamp: May 08, 2023, 04:30:11 am
content: QuoteHey... it could be worse. They could be building planes, cars, heart valves or pacemakers. As long as they stick to phone systems, the world is safer.