hissing sound inside on acceleration-1999

I seem to be hearing a vacuum leak sound, under acceleration only, inside the car eminating from the passengers-side.although none of the climate control levers seem to be vacuum actuated. car seems to be running great. HVAC okay. Is this normal interior noise for the 1.8L engine?

the controls may have a cable on them but they may connect to a vacuum control for the damper door for heat and cooling