Design of a sound source phantom with uniform surface signal

Documenting the characteristics of contact body-sound sensors is important since they are an integral part of vibroacoustic experiments. To facilitate sensor testing, a repeatable sound source is desirable. The purpose of this study was to construct a sound source phantom for testing sensors with different sizes. To facilitate accurate comparison of the characteristics of these sensors a uniform acoustic signal at the phantom surface is required. The acoustic output at the phantom surface was documented using a laser Doppler vibrometer. A rigid plate was embedded within the phantom to help achieve a uniform acoustic signal at the surface. Measurements showed that the surface acoustic output has high spatial uniformity (about ±1 dB over a 6 cm diameter). The developed phantom is compact (> 250 ml), easy to construct, requires no special storage, and has mechanical properties similar to soft tissue.