# COO - Baby Sound Therapy — A Co-regulation Companion

> Co-regulation sound companion for parents to calm infants by self-regulating. (iPhone/iPad app by alexandra stark.)

- Source: https://appshunter.io/ios/app/coo-baby-sound-therapy/id6764710380 (this page in markdown: same URL + `.md`)
- Developer: [alexandra stark](https://appshunter.io/developer/1895888330)
- Category: Health & Fitness
- Price: Free with in-app purchases
- Rating: 5.00/5 from 3 App Store ratings
- Age rating: 4+
- Requires: iOS 15.0 · 126 MB
- Languages: American English
- Released: 2026-05-06
- Data updated: 2026-09-14
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/coo-baby-sound-therapy/id6764710380/reviews.md

## What is COO?

Some nights you're pacing the hallway, the backyard, the whole neighborhood with your crying infant, running out of ideas and running low on yourself.

COO was built for that moment.

It's a sound companion for parents and caregivers - layered audio designed to help you settle your baby by first settling yourself. When your nervous system regulates, your baby's follows. This is co-regulation: the science behind every instinct you already have.

  Six sound environments, each designed for a specific moment:
  - Calm & Settle - for the everyday overwhelm
  - Big Feelings - when emotions are running high
  - Bonding - skin to skin, fully present
  - Immune Support - frequency support during illness
  - Teething & Comfort - for the hard nights
  - Sleep Wind-Down - the long, slow drift into rest

Each playlist layers pink or brown noise, a binaural drone tuned to a Solfeggio frequency, a heartbeat at 68 bpm, and a soft melodic overlay, set at a comfortable default volume for each layer.

COO Premium unlocks all six playlists, the sound mixer, Play All with a drag-to-reorder queue, and extended sessions for an effortless hands-free experience. Try all of it free for 7 days, no card required, then keep it for a one-time $3.99 whenever you are ready.

  Made for caregivers, by a caregiver.

## Key features

- Six specialized sound environments
- Layered audio with pink/brown noise
- Solfeggio frequencies and heartbeat sounds
- Sound mixer and drag-to-reorder queue
- Extended session options
- 7-day free trial

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| COO Premium | $3.99 | one-time |



## Frequently asked questions about COO

### What is COO - Baby Sound Therapy?

COO - Baby Sound Therapy is a sound companion designed to help parents and caregivers self-regulate their nervous systems, which in turn aids in settling their infants. It utilizes layered audio with specific frequencies and sounds to create calming environments.

### How does COO - Baby Sound Therapy work?

The app offers six distinct sound environments, each with a unique combination of pink or brown noise, Solfeggio frequencies, a heartbeat at 68 bpm, and melodic overlays. The principle is that when the caregiver regulates, the baby's nervous system follows.

### What are the different sound environments available in COO - Baby Sound Therapy?

The six sound environments include Calm & Settle, Big Feelings, Bonding, Immune Support, Teething & Comfort, and Sleep Wind-Down, each tailored for specific parental and infant needs.

### What features are unlocked with COO Premium?

COO Premium unlocks all six playlists, a sound mixer, a 'Play All' feature with a drag-to-reorder queue, and extended session durations for a more comprehensive and hands-free experience.

### How much does COO Premium cost?

COO Premium can be tried for free for 7 days without requiring a card. After the trial, it is available for a one-time purchase of $3.99.

### Does COO - Baby Sound Therapy have ads?

No, this app does not contain advertisements. The monetization is solely through an optional in-app purchase for premium features.

### What devices is COO - Baby Sound Therapy compatible with?

COO - Baby Sound Therapy is designed for iOS devices, including iPhone, iPad, and iPod.

### How often is COO - Baby Sound Therapy updated?

The latest version of COO - Baby Sound Therapy is 1.0.5, and it was last updated on September 9, 2026. Updates typically focus on refining features and ensuring stability.

## Version history (last 5 releases)

### 1.0.5 — 2026-09-09

Try COO Premium free for 7 days. All six playlists, the sound mixer, extended 15 and 30 minute sessions, and Play All with your own queue order. No card required.

Also fixed: the premium screen now recognizes you if you have already unlocked COO.

### 1.0.4 — 2026-06-25

Play All mode - queue all six playlists in one continuous session and arrange them in your custom order. UI refinements throughout.

### 1.0.3 — 2026-05-25

In-app Purchase bug fix.

### 1.0.2 — 2026-05-09

Bug fixes and performance improvements.

### 1.0.1 — 2026-05-06

Bug fix for Premium

## Apps similar to COO

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Meditation for Kids Sleep](https://appshunter.io/ios/app/meditation-for-kids-sleep/id1417918068) | 4.5 (743) | Free | Health & Fitness |
| [Focal Physical Therapy](https://appshunter.io/ios/app/focal-physical-therapy/id6748228778) | 5.0 (1) | Free | Health & Fitness |
| [Vīrya Guided](https://appshunter.io/ios/app/virya-guided/id1562147704) | 4.0 (5) | Free | Health & Fitness |
| [Earth Yoga & Spa](https://appshunter.io/ios/app/earth-yoga-and-spa/id6470240213) | — | Free | Health & Fitness |
| [TQF Coaching](https://appshunter.io/ios/app/tqf-coaching/id6763563175) | — | Free | Health & Fitness |
| [Frequency: Healing Sounds Hz](https://appshunter.io/ios/app/frequency-healing-sounds-hz/id6743464946) | 4.7 (276) | Free | Health & Fitness |

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-14.*