> For the complete documentation index, see [llms.txt](https://docs.timeinpixels.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.timeinpixels.com/nobe-omniscope-for-ipad/audio.md).

# Audio

The small segmented bars beside the source selector indicate incoming audio levels. The label under them shows the channel count, for example **2 ch**, or **Silent** when channels are present but carry no signal. A crossed-waveform icon means no audio channels are currently available. Tap the audio area to inspect audio details.

## Listen to the input

When audio is available, the speaker button appears in the toolbar. Tap it to enable **Monitor Audio**. Playback uses the iPad's current audio route. Metering and listening are separate: you can measure audio without playing it through the speakers.

NDI and SRT can carry audio, depending on the sender. Local video can contain an audio track. SeeMo supports mono or stereo AAC audio. ScreenPort SDK-enabled builds support channels 1/2, duplicating mono audio, including compressed Opus. A video-only source does not gain audio simply by enabling monitoring.

For a local video, **Video Playback → Mute Playback** silences playback while keeping metering active.

## Built-in camera microphone

Select a built-in camera, then tap the microphone button to enable **Camera Microphone**. Grant microphone access when asked. Once audio arrives, use the speaker button to listen.

Use headphones when monitoring the microphone to avoid feedback between the iPad's microphone and speakers.

## Stereo and loudness

Assign **Goniometer** or **Loudness Meter** to a grid cell:

* **Goniometer:** select a stereo pair when more than two channels are available. Inspect the trace and correlation, and adjust trace style or peak hold in its menu.
* **Loudness Meter:** inspect momentary, short-term and integrated LUFS, loudness range and true peak. Pause or reset the measurement from its menu.

<figure><img src="https://565437294-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MFqn5MuayPgQPMZ9pwf%2Fuploads%2Fgit-blob-bdb6ed388e3e832cf3d84f883419342b9623ebd2%2Fomniscope-ipad-loudness-meter.png?alt=media" alt="iPad in portrait with an Accsoon SeeMo source, a Loudness Meter showing M, S and I bars with LUFS values, a Waveform and a Vectorscope"><figcaption><p>Loudness Meter next to video scopes. M, S and I are momentary, short-term and integrated loudness in LUFS; the toolbar shows 2 ch of incoming audio.</p></figcaption></figure>

Each Loudness Meter has its own history. Reset at the start of a program you want to measure. Seeking or looping a video resets the measurement, so a loop is not a continuous program measurement across repetitions.

## Source limitations

SeeMo audio must be mono or stereo AAC. ScreenPort is available only in SDK-enabled builds, not the distributed beta. Still images have no audio. USB capture audio depends on the capture device and the audio path available to the app; do not assume that a working picture guarantees audio support.

If audio breaks up, compare the toolbar meter with what you hear: continuous levels with broken playback help distinguish an output-monitoring problem from missing incoming packets. Record the source, sample rate/channel count, audio route and any recent orientation or settings changes in your bug report.