Settings Reference

This page documents every setting available in the Chirps Settings sheet, grouped by section.

Open Settings by tapping the sliders icon (three horizontal lines) in the top bar.

Note on Visualisation settings: Plot mode, colour palette, inverted colour map, waveform colour, and frequency range are not in the Settings sheet. Swipe left/right to switch between Spectrogram and Waveform. Long-press the plot while the stream is running to reveal the waveform or spectrogram tools. See the Visualisation section below for descriptions of each option.

Input

Settings in this section configure the audio input device and recording format. The stream must be stopped before most input settings take effect.

Guide and Info

Opens the in-app Guide screen. Contains a quick reference to the interface and basic usage.

Input Device

Selects the active microphone or audio interface. The list includes all devices that have been detected.

Tap the ↺ refresh button to re-probe connected devices.
If a device does not appear, stop the stream, unplug and replug the device, and refresh.
Changing the selected device while the stream is stopped triggers an automatic capability refresh.

Input Channel

For multi-channel devices, selects which channel is captured. Only one channel is captured at a time. The available channels are populated from the selected device.

Sample Rate

Sets the preferred sample rate. The picker is based on iOS route discovery, device probing, cached authentic capabilities, and actual runtime formats observed during streaming. If the hardware cannot start at the requested rate, Chirps adjusts to an available rate and logs the change. Custom rates discovered during probing or actual streaming are kept with the device and shown with a Custom tag.

Record File Bit Depth

Sets the WAV file bit depth for recordings. Options: 16-bit, 24-bit, 32-bit. The engine format shown in Diagnostics is separate from the file bit depth and may not be the same as a USB device’s hardware converter depth.

Hardware Input Gain

Visible only when the selected device exposes adjustable input gain to iOS. A normalised slider (0.00–1.00) controlling the device’s own ADC gain. Stored per device.

Output

Output Route

Controls where monitoring audio is sent.

Option	Behaviour
Automatic	Follows the selected or system route. This may be the device speaker, wired headphones, AirPods, or an external device output if iOS keeps that route active. Recommended for most use.
Device Speaker	Requests the built-in speaker. Available only when iOS can keep that combination stable.

Haptic Feedback

HET Haptic (toggle)

Enables haptic feedback during heterodyne monitoring. When active, the Taptic Engine fires a pulse whenever the HET peak level crosses the threshold. Only available on devices with a Taptic Engine.

Threshold

Slider (0.00–1.00). The minimum HET peak level required to trigger a haptic pulse. Lower values respond to faint signals; higher values suppress background noise triggers.

Haptics stay active while the signal remains above the threshold, and louder calls feel stronger.

Layout Settings

Screen Orientation

Locks or follows the device’s physical orientation.

Option	Behaviour
Follow Device	Follows the device orientation within Chirps’ supported orientations.
Portrait	Forces portrait regardless of physical orientation.
Landscape Left	Forces landscape (home/volume buttons on right).
Landscape Right	Forces landscape (home/volume buttons on left).

Landscape Placement

In landscape, sets where the control panel sits relative to the plot. On wider landscape layouts this is top/bottom. Has no effect when the current layout is portrait.

Recording

Destination

Shows the current recording folder path. Tap Choose Folder to open the system folder picker and select any Files-accessible location. Tap App Documents to reset to the default internal directory.

Ring Buffer (2–10 s, step 0.1 s)

The duration of the rolling audio buffer held in memory while the stream is running. This is the source for pre-trigger capture and the scrolling spectrogram history. Longer values require more RAM. Takes effect on restart and is disabled while the stream is running.

Pre Trigger (0.5–9.5 s, step 0.5 s)

How far back into the ring buffer Chirps reaches when a recording starts. The pre-trigger duration cannot exceed the ring buffer duration minus the app’s safety margin.

Post Trigger (0.5–10 s, step 0.5 s)

How long recording continues after you tap the stop button. The file closes automatically when the post-trigger expires.

Visualisation

These settings affect the live display. They are accessed from the plot panel, not from the Settings sheet.

Plot Mode

Switches the live display between Spectrogram and Waveform. Swipe the plot panel left or right to switch. Can be changed while the stream is running.

Colour Palette

Selects the colour palette for the spectrogram. Long-press the spectrogram while the stream is running, then use the paintbrush tool. Options: Blue, Autumn, Bloom, Flux, Solaris, Grey. Changes take effect immediately. See Live Spectrogram — Colour Palettes for descriptions.

Inverted Colour Map

Reverses the palette so that louder signals are darker. Useful for printing and some publication styles.

Waveform Colour

Selects the colour style for the waveform display. Long-press the waveform while the stream is running, then use the paintbrush tool. Options: Blue, Amber, Mint, Ice, Rose.

Spectrogram Min Frequency / Max Frequency

Constrains the visible frequency range. Useful when working with ultrasonic devices to focus the display on the frequency band of interest and suppress out-of-band noise. Changing these limits may restart the spectrogram view, but it does not stop the audio stream.

Diagnostics

Actual Sample Rate

Read-only. Shows the sample rate negotiated with the hardware after the stream starts. May differ from the preferred rate.

Engine Format

Read-only. The audio engine’s internal processing format and bit depth.

Record File Format

Read-only. The PCM format that will be written to WAV files.

Buffer Frames

Read-only. The hardware I/O buffer size in frames. Smaller values mean lower latency; larger values are more stable on slower hardware.

Event Log

Expandable log of recent route, audio configuration, recording, and renderer fallback events. The newest entries are shown at the top. Tap Copy to copy the full log to the clipboard for pasting into a support email. The log persists across launches.