Music devices for the fetus? An evaluation of pregnancy music belts.

BACKGROUND: The implementation of music during pregnancy is a topic of interest for parents-to-be accompanied by a growing commercial interest. We evaluated acoustic properties of commercially available music devices.

MATERIALS AND METHODS: Sound characteristics of three different music devices designed for fetal acoustical stimulation were analyzed. A white noise sample was presented at a high volume to produce a standardized acoustic stimulus. Sound emissions were registered for each loudspeaker with a sound level meter in order to document the sound pressure levels (SPLs) and to analyze the long-term averaged spectra (LTAS) with the help of PRAAT-sound-analyzing software. Measurements were conducted in open air and under attenuated conditions with interposition of a pork uterus of 5 mm thickness covered by porcine tissue from the abdominal wall of either 3 or 5 cm thickness.

RESULTS: Under attenuated conditions, SPLs of all three devices were hardly detectable and interfered with the basal noise of around 50-55 dB (SPL), particularly low and high frequencies ranges were attenuated.

CONCLUSION: Pregnancy music belts seem to be a useless tool to support fetal development. The poor sound characteristics of the loudspeakers and the concept of an isolated stimulation appear not promising to effectively support the complex multimodal maturation of the sensory system. Traditional implementation of music appears maternal singing appears more reasonable.