The last six seconds. Each mark above the wave is a beat the page counted.
Everything the mic hears, low pitches on the left. The lit band is what you keep. The rest is turned down.
Almost every bad recording comes from air leaking or something rubbing. The body sounds are faint, so any leak lets the room in.
The mic should sit snug in the tube with tape or putty around it. If the other earpiece is still attached, plug it. Tap the chestpiece before you start: you should hear a sharp thump.
Press the flat side of the chestpiece against the skin and don't slide it. Moving even slightly makes a scraping sound much louder than a heartbeat. Keep the tube from touching clothes, fur or the couch.
Fur is the biggest problem. Part it, or dampen it a little, so the chestpiece touches skin. The heart is loudest on the left side of the chest, just behind the elbow when the front leg is at rest. For lungs, listen higher up and further back on both sides. A calm, lying-down dog makes the best recording, and asleep is better still.
Heart: left of the breastbone, about the level of the nipple, sitting still. Lungs: the back, both sides, while breathing slowly through the mouth.
Fans, air conditioning and a TV all come through. Turn off what you can. For steady sounds like a fan, use Learn the room: lift the chestpiece off the body, hold it still, tap the button, and wait three seconds. Then turn on Room cleanup. It won't remove talking or barking.
Start the Boost low and raise it slowly. If the dot next to the number says too loud, turn Boost down: the sound is clipping and the numbers get worse, not better.
The page finds the repeating pattern in the sound and times it. When the pattern is clear, it shows a number. When it isn't, it shows two dashes instead of guessing.
Adults at rest: usually 60 to 100 beats a minute. American Heart Association.
Dogs at rest: 70 to 120. Merck Veterinary Manual, resting heart rates table.
Dogs' hearts speed up as they breathe in and slow as they breathe out. So a dog's beat spacing often reads as uneven here, and in a healthy dog that's normal. Vets call it sinus arrhythmia.
Adults at rest: about 12 to 20 breaths a minute.
Dogs asleep or resting: 15 to 30 is normal. Staying above 30 is a reason to call the vet. VCA; Cardiac Education Group.
Breathing is quieter and slower than a heartbeat, so the sound-based count needs about 20 seconds and a still, quiet room. For the number you log, counting chest rises by eye is still the more reliable method.
It counts and times sounds. It doesn't recognize murmurs, crackles or wheezes, and a number here doesn't mean everything is fine. Its best use is a recording you can play for the vet or doctor, and comparing one day's sound with another's.