Hush Owlet

Details

The Owlet Dream Sock can provide insightful information on your child's sleep, but if connection or fit issues occur, a loud alarm (in the form of a "lullaby" playing over a 1980's style 90dB buzzer) plays that can wake up the baby or parent. This hack assumes you are using the device for it's intended purpose for sleep quality tracking, and not a pseudo-medical device.

Disclaimer: This is not intended to be used as a medical device. This hack almost surely voids the warranty on the device.

Components

1 × Owlet Dream Sock https://amzn.to/3ORSBiB

1 × T6 torx screw driver https://amzn.to/3d0I3R5

1 × X-Acto knife or box cutter with fresh blade

Build Instructions

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1

Remove the pad on the back that hides the screws

The green pad on the back hide the screws that hold the base station together.

It was surprisingly easy to remove with just my finger nails by slowly lifting each edge in a circular motion until the whole pad came off
2

Remove the four screws to disassemble the base station

The screws require a T6 "security bit" Torx driver. These can be found in most electronics fix it kits

Removing the screws on the bottom allows you to remove the top cover
3

Understanding how to disconnect the speaker

moThe big black device in the middle of the printed circuit board (PCB) is the speaker (aka buzzer, or transducer). You can see a little slit in the one side where the sound comes out.
There is a back side to the circuit board that you cannot easily see since the board is taped in place. If you'd like to see the backside of the board, see the photos in the FCC application
The white sticker on top of the speaker was placed after the PCB was manufactured as a product ID for the PCB. By removing the speaker, you can see the identification markings on the speaker.
The speaker is a "SMT1010-3.6H3.2 LF" by BeStar Acoustic. From the datasheet we can see that only two of the four solder legs do anything: the one by the (+) sign, and the one across from it (the two legs on the left of the photo above). The datasheet also shows the example circuit for the speaker.
Zooming in, we can see the transistor (Q4), the diode (D8), and the resistor (R1) that are part of the circuit that drives the speaker. A simple explanation of this circuit is that something (the main processor on the base station) generates a sound wave signal that activates the base of the transistor and allows power to flow from "Ec+" through the transducer, through the transistor (from collector to emitter), and then to ground.
On three leg transistor chips like this, the single leg on the top is the collector.
in the figure below, I tried to highlight the trances from the transistor to the speaker, diode, and "test point". The easiest way to cut off the speaker from the driver will be to cut the trace from the collector to the diode.