Ubuntu 26.04 LTS GNOME - Distorted microphone audio in ChatGPT Voice and YouTube (PipeWire + ALC256)

[Can]

Hello Ubuntu community,

I am using Ubuntu 26.04 LTS with GNOME. My internal microphone is detected correctly by the system, but I have a problem with browser-based voice applications.

When I use:

• ChatGPT Voice

• YouTube voice search

• Other browser-based speech recognition services

the microphone works, but the audio quality is very poor.

Symptoms:

• My voice sounds distorted.

• Speech recognition often misunderstands words.

• The microphone input seems noisy or incorrectly processed.

• The problem is mainly noticeable inside the browser.

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System information

Ubuntu: 26.04 LTS
Desktop Environment: GNOME
Audio System: PipeWire
PipeWire version: 1.6.2
WirePlumber version: 1.6.2

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Microphone hardware

Internal microphone:

ALC256 Analog
Ryzen HD Audio Controller

The microphone is detected by ALSA:

**** CAPTURE Hardware Devices ****
card 1: Generic_1 [HD-Audio Generic]
device 0: ALC256 Analog [ALC256 Analog]

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PipeWire status

wpctl status -n shows:

Sources:
* 59. alsa_input.pci-0000_04_00.6.analog-stereo [vol: 1.00]

Firefox is detected by PipeWire:

Firefox [1.6.2]

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What I have checked

• Microphone permissions in the browser are enabled.

• The microphone is detected by the system.

• PipeWire and WirePlumber are running correctly.

• The issue is not that the microphone is missing; the problem is the input quality.

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Questions

1. Are there recommended PipeWire or WirePlumber settings for ALC256 microphones on Ubuntu 26.04 LTS?

2. Could microphone boost, sample rate, or audio profile settings cause distorted input in WebRTC applications?

3. Is there any Firefox-specific configuration needed for better PipeWire microphone handling?

4. Should I adjust settings using pavucontrol, wpctl, or another modern PipeWire tool?

I can provide additional logs or command outputs if needed.

Thank you for your help.

[peterwhite23]

Try lowering the input volume; perhaps disable mic boost. Distortion can be caused by gross over-amplification which clips the sine waves and makes them look more like squares; you do not want to listen to a square wave. The hard edges mean there are a lot of high frequency overtones.

Another extreme is when the input is so low that you have to crank up the amp, because the signal-to-noise ratio is really bad in such cases; noise gets amplified too.

Other than that, I can only think of low sample rate.

pw-top

run in a terminal should tell you, if that’s the case.

[Can]

Thank you for the suggestion.

I checked the input level and reduced the microphone volume from 100% to around 50%. After lowering the input volume, the situation improved significantly.

I also checked PipeWire with pw-top and the sample rate is 48000 Hz, so it looks normal.

At the moment:

• ChatGPT Voice recognition is much more accurate.

• YouTube voice search works better.

• The recorded microphone audio is clearer and no longer sounds heavily distorted.

It seems the main issue was probably excessive microphone gain/input volume causing clipping.

I will keep testing for a while to make sure the problem does not come back after reboot or during longer usage.

Thanks for pointing me in the right direction.

[peterwhite23]

Glad I could help. Mind marking my comment as the solution then?

[Can]

Sure, I marked your comment as the solution. Thank you very much for your help and support.

Kind regards.