How coloured lenses aid singing students

Sussane Towers operatic arts and theatere direcotr with expertise in the area of vocal training has been aware of light on audio perception for some time and recently found that the concept of wearing coloured lenses will  help improve singing. From her observations although varying from student to student, she found in the main the light reduction not only aids them to sing in tune with confidence and increased awareness of  their musicality but enables them to “hear” when they are “out” of tune.

As a classically trained singer myelf who has taught in colleges and  also privately  I can see that this could be used as a sensory analogy to aid the perception of hearing the sound ,but I’m not sure that this is anything other than that. What is the  light reduction doing? Is it affecting  the wavelength of sound? or is  merely helping the students to perceive the sound better?

Would these students be able  “hear” just as well if they were blindfolded in order to “feel”  the physicality of producing a sound?

I welcome comments from singers  teachers and  music colleges.Email