Voicemail App Flicker?

[cslo5]

Something I had just noticed. In the voicemail app on 4.3 when I listen to a message WITHOUT speaker on and I hold the phone up to my ear, when I bring the phone down when the screen is black, the notification bar will flicker. So I tried it and held my finger up to the speaker at the top and the sensors, the screen goes black, then the notification bar flickers. Any other Sprint users confirm this in 4.3?

Thanks!