Transducer

An electroacoustic transducer, comprising:

• a piezoelectric part comprising a piezoelectric material having a first acoustical impedance;
• a substrate part comprising a material having a second acoustical impedance;
• and
• an intermediate part comprising a material having a third acoustical impedance and at least partially between the piezoelectric part and the substrate part for acoustical communication therewith;
• wherein an acoustical thickness of the intermediate part between the piezoelectric part and the substrate part is less than 0.2Λ′, wherein Λ′ is an acoustical wavelength in the material of the intermediate part;
• and
• wherein the first acoustical impedance and the second acoustical impedance each has a respective value within a range of values for which the value of the third acoustical impedance is
• an upper limit if an acoustical thickness of the piezoelectric part is less than 0.4Λ, or
• a lower limit if said acoustical thickness of the piezoelectric part is greater than 0.4Λ,
• wherein Λ is an acoustical wavelength in the material of the piezoelectric part.