Even tone deaf students can perform this experiment but the sonometer must be correctly tensioned or spurious harmonics interfere with the frequency determination.
This is easier to use than the sonometer with weights, but the tension cannot be measured quantitatively.
They are looking for a sonometer for automatic interaction with an automatic pager, to implement dynamical noise maps automatically.
The two sonometers were disposed in planes forming 90 degrees with the vacuum cleaner.
The differential sonometer was invented by the French acoustical apparatus manufacturer, Marloye, ca. 1840.