Scientists readily admit that the motion of the observer cannot change the wavelength of SOUND waves (and therefore the speed of the waves does vary with the speed of the observer):

http://faculty.washington.edu/wilkes...erference..pdf
"Sound waves have speed c, and f and λ are related by c=λf. For an observer moving relative to medium with speed u, apparent propagation speed c' will be different: c'=c±u. Wavelength cannot change - it's a constant length in the medium, and same length in moving coordinate system (motion does not change lengths). Observed frequency has to change, to match apparent speed and fixed wavelength: f'=c'/λ."

Most scientists are afraid to openly declare that the motion of the observer cannot change the wavelength of LIGHT waves as well but some are not:

http://www.einstein-online.info/spotlights/doppler
Albert Einstein Institute: "The frequency of a wave-like signal - such as sound or light - depends on the movement of the sender and of the receiver. This is known as the Doppler effect. (...) Here is an animation of the receiver moving towards the source:

http://www.einstein-online.info/imag...ler_static.gif (stationary receiver)

http://www.einstein-online.info/imag...ector_blue.gif (moving receiver)

By observing the two indicator lights, you can see for yourself that, once more, there is a blue-shift - the pulse frequency measured at the receiver is somewhat higher than the frequency with which the pulses are sent out. This time, the distances between subsequent pulses are not affected, but still there is a frequency shift: As the receiver moves towards each pulse, the time until pulse and receiver meet up is shortened. In this particular animation, which has the receiver moving towards the source at one third the speed of the pulses themselves, four pulses are received in the time it takes the source to emit three pulses."

Since "four pulses are received in the time it takes the source to emit three pulses", the speed of the pulses relative to the receiver is greater than their speed relative to the source, in violation of Einstein's relativity..

Pentcho Valev