FDSoundActivatedRecorder

 * V
 * O                 /-----------\
 * L                /             \
 * U          Rise /               \ Fall
 * M              /                 \
 * E  -----------/                   \-----------
 *
 *       Quiet   |   Recorded file   |   Quiet

Example

To run the example project, clone this repo, and open Example.xcworkspace from the iOS Example directory.

Installation

Add this to your project using Swift Package Manager. In Xcode that is simply: File > Swift Packages > Add Package Dependency... and you're done.

License

FDSoundActivatedRecorder is available under the MIT license. See the LICENSE file for more information.

Features

• You can start recording when sound is detected
• Sound stops recording when the user is done talking
• Works with ARC and iOS 16+

Usage

Import the project with:

import FDSoundActivatedRecorder

Then begin listening with:

self.recorder = FDSoundActivatedRecorder()
self.recorder.delegate = self
self.recorder.startListening()

A full implementation example is provided in this project.

Regular recorder

If you want to use it as a regular recorder, without trimming the audio, you can tweak the Configuration to achieve that.

Full API

The full API, from FDSoundActivatedRecorder.swift is copied below:

// FIXME: PASTE HERE

Technical discussion

This library is tuned for human speech detection using Apple retail iOS devices in a quiet or noisy environement. You are welcome to tune the audio detection constants of this program for any special needs you may have. Following is a technical description of how the algorithm works from FDSoundActivatedRecorder.swift.

 * V
 * O                 /-----------\
 * L                /             \
 * U          Rise /               \ Fall
 * M              /                 \
 * E  -----------/                   \-----------
 *
 *       Quiet   |   Recorded file   |   Quiet

• We listen and save audio levels every INTERVAL
• When several levels exceed the recent moving average by a threshold, we record
• (The exceeding levels are not included in the moving average)
• When several levels deceed the recent moving average by a threshold, we stop recording
• (The deceeding levels are not included in the moving average)