dB SPL Calculation is not making sense- values are seemingly too high
The sensitivity is measured at 1m distance, in free space.
In free space, for each halving of distance, sound amplitude goes up by 6dB. So 94 dB at 1m will be 100dB at 50cm, 106dB at 25cm, 112dB at 12.5cm, etc.
Also, the microphone is not measuring in free space, but in a sealed enclosure, so expect higher amount of sound pressure to couple from buzzer to microphone than in free space.