The Womb Effect — Mother's Heartbeat

What the baby hears predominantly is the mother's heartbeat. How the baby perceives the sound of the heartbeat is crucial. Most off-the-shelf baby sleep tapes, CDs and audio products offer the sound of synthesized heartbeats or ultrasound translations, but the Sound Sleep for Babies™ (formerly known as the BabySleep System™) audio track uses actual mother's heartbeat recorded through a condenser microphone adapted to the "bell" of a stethoscope.

An intrauterine heartbeat recorded through ultrasound or doppler methods produce a sound that is NOT AT ALL what the baby hears inside the womb.

For instance, that "swishing" sound that is popular in ultrasound monitoring (called "doppler ultrasonography") is caused by the machine itself. That is NOT what it sounds like inside the body.

Listen to the difference:

Heartbeat as heard through UltraSound Monitor

Heartbeat as heard through from the baby's perspective

The sound of the mother's heartbeat that the baby actually hears inside the womb is totally different than any sound that exists outside the womb. No other product on the market has attempted to work from within the womb itself.

The Sound Sleep for Babies (formerly known as the Baby Sleep System) technology uses recordings taken from INSIDE the body, not OUTSIDE. As you listen to the CD, it sounds as if you (the listener) are underwater.... just as your baby remembers it.

The Resting Heartbeat

Actual recordings of mother's heartbeat were taken, then slowed down to a consistent 72 beats per minute. This is the "tempo" of a perfectly rested mother's heartbeat. Tests have proven that the prenatal baby is most relaxed when the mother is calm and rested.

Studies conducted by the late Dr. Lee Salk, eminent Child and Family authority, showed that playing a heartbeat sound recorded from the chest and set to a metronome speed of 72 BPM had various positive effects on newborn babies. The babies gained weight at a faster rate, and they were found to breathe deeper and more regularly when compared to babies who were not exposed to the heartbeat sound. Salk also noted heart rates played at more than 90 BPM resulted in increased excitability and agitation among those babies. A mother's heart rate can exceed 120 BPM during moments of physical stress.

Notice the graphical difference between a rested heartbeat at 72bpm vs. 120bpm and slightly erratic.

Mother's heartbeat at 120 beats per minute, and slightly erratic

Mother's heartbeat at 72 beats per minute, calm and steady