Einsteinians readily teach that a moving light source produces exactly the same Doppler effect as a moving sound source - allegedly the wavefronts bunch up (the wavelength decreases) in front of the moving light source and this is the cause of the frequency shift measured by the observer:

https://www.youtube.com/watch?v=vDvIhiCnatE
"Doppler Effect In Light Waves"

https://www.youtube.com/watch?v=h4OnBYrbCjY
"The Doppler Effect: what does motion do to waves?"

"Doppler effect for moving source" is just as important as "Doppler effect for moving observer" but in the latter case Einsteinians only reluctantly consider sound waves and light waves in parallel. The reason is that the speed of the waves (relative to the observer) varies with the speed of the observer - a fact fatal for Einstein's relativity and explicitly admitted only for sound waves:

http://faculty.washington.edu/wilkes...erference..pdf
"Sound waves have speed c, and f and L are related by c=Lf. 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'/L."

Yet for "Doppler effect for moving observer" Einsteinians do carry out the analogy between sound and light - they admit that "motion does not change lengths" - but always stop short, as though by instinct, at the threshold of the dangerous thought:

"...apparent propagation speed c' will be different: c'=c±u."

http://www.einstein-online.info/spotlights/doppler
"Here is an animation of the receiver moving towards the source. (...) 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..."

http://ebooks.adelaide.edu.au/o/orwe...hapter2.9.html
"Crimestop means the faculty of stopping short, as though by instinct, at the threshold of any dangerous thought. It includes the power of not grasping analogies, of failing to perceive logical errors, of misunderstanding the simplest arguments if they are inimical to Ingsoc, and of being bored or repelled by any train of thought which is capable of leading in a heretical direction. Crimestop, in short, means protective stupidity."

Pentcho Valev