To clear up some confusion:
Many textbooks and internet resources are completely in disagreement when it comes to the meaning of the 'rayl.'
Our physics teacher went off wading through stacks of resources in search of the true meaning. He found four definitions all up, however the clear consensus was that the SI unit (kg.m^-2.s^-1) is the real rayl. (like the Newton refers to kg.m.s^-2)
So, multiplying the acoustic impedance by 10^6 (commonly done to make conveniant numbers when dealing with the acoustic impedances of various body parts) results in units called the megarayl, NOT the rayl.
Many textbooks and internet resources are completely in disagreement when it comes to the meaning of the 'rayl.'
Our physics teacher went off wading through stacks of resources in search of the true meaning. He found four definitions all up, however the clear consensus was that the SI unit (kg.m^-2.s^-1) is the real rayl. (like the Newton refers to kg.m.s^-2)
So, multiplying the acoustic impedance by 10^6 (commonly done to make conveniant numbers when dealing with the acoustic impedances of various body parts) results in units called the megarayl, NOT the rayl.