Spek is an acoustic spectrum analyser written in C++. It uses FFmpeg libraries for audio decoding and wxWidgets for the GUI.

AirPods Sound Quality Fixer And Battery Life Enhancer For MacOS
Fixes sound quality drops when using AirPods with Macs. It forces the default audio input to be the built-in microphone instead of AirPods' microphone so MacOS doesn't have to mix down the output. It also increases battery life because AirPods doesn't have to broadcast sound back. If you have more input devices you can select which device you want to force over the AirPods microphone.

MediaMate provides fresh visuals for the Volume, Display and Keyboard Brightness HUD and introduces a new Now Playing HUD!
Features

A Now Playing HUD which shows the current playing media, and provides quick controls such as play/pause and scrubbing. It can be shown "inside" the notch, or in a separate bubble.

An audio, brightness and keyboard brightness HUD which replace the native HUDs.

iOS-styled theme, circular theme, notch theme and the classic theme.

Audio output icons to quickly see the output device in the audio HUD.

Shortcuts to control keyboard brightness

Focus Filters: hide HUDs when a focus mode is enabled

Lots of settings to customise the app to your needs

Compatibility

Touchbar & Non-touchbar macs are supported

Extended display brightness & volume support with Lunar or BetterDisplay (others are not supported)

Now Playing works with most apps, including Apple Music, Spotify, Chrome, ...

Control Apple Music with this simplified controller that has the look and feel of QuickTime 7.

Compare qualities of Opus audio encoded with different bitrates

Easy, fast and powerful audio editor

Background Music, a macOS audio utility: automatically pause your music, set individual apps' volumes and record system audio.

Quickly and easily transcribe audio files into text with OpenAI's state-of-the-art transcription technology Whisper. Whether you're recording a meeting, lecture, or other important audio, MacWhisper quickly and accurately transcribes your audio files into text.

Features

Easily record and transcribe audio files

Just drag and drop audio files to get a transcription
.srt & .vtt subtitles export

Get accurate text transcriptions in seconds (~15x realtime)

Search the entire transcript and highlight words
Supports multiple languages (fastest model is English only)

Copy the entire transcript or individual sections
Supports Tiny (English only), Base and Large models

Reader Mode
Edit and delete segments from the transcript
Select transcription language (or use auto detect)
Supported formats: mp3, wav, m4a and mp4 videos.

A small tool for changing sound volume even for aggregate devices cause native sound volume controller can't change volume of aggregate devices (it was always pain in the ass with my laptop).

Features:

Changing sound volume of every device (even virtual aggregate device volume by changing volume of every device in aggregate device)
Changing default output device
Native appearance (looks like native volume controller)
Media keys support

I think it can be very useful if you're using VoodooHDA with 4.0+ sound on the board (my use case), but you can find another use cases.

Mixxx integrates the tools DJs need to perform creative live mixes with digital music files.
Whether you are a new DJ with just a laptop or an experienced turntablist, Mixxx can support your style and techniques of mixing.

Audiobookshelf is a self-hosted audiobook and podcast server.

deemix (lowercase) is a barebone deezer downloader library built from the ashes of Deezloader Remix.

Say goodbye to proprietary music players filled with ads, tracking, and profiling.
Nuclear empowers you to listen to what you want, where you want, and how you want, for free.

🍓 Jam is an open source alternative to Clubhouse, Twitter Spaces and similar audio spaces.

With Jam you can create audio rooms that can be used for panel discussions, jam sessions, free flowing conversations, debates, theatre plays, musicals and more. The only limit is your imagination.

Use deep fake tech to say stuff with your favorite characters.

Separate voice from music out of a song free with powerful AI algorithms

BlackHole is a modern macOS virtual audio driver that allows applications to pass audio to other applications with zero additional latency.

SonoBus is an easy to use application for streaming high-quality, low-latency peer-to-peer audio between devices over the internet or a local network.