What is the highest typical ambient noise level where audio paging becomes unintelligible?

75 dB represents a moderately loud environment such as a busy restaurant or production area where paging systems remain intelligible with adequate amplification and speaker placement.

85 dB is a high ambient noise level but properly designed paging systems with sufficient gain and speaker density can still achieve acceptable speech intelligibility at this level.

At 95 dB ambient noise, the masking effect of background noise overwhelms the audio paging signal at practical amplifier output levels, rendering speech content unintelligible to listeners. This is the recognized upper boundary in audio system design beyond which standard paging amplification cannot compensate for noise interference. System designers must consider supplemental alerting methods such as visual strobes or electronic messaging displays when ambient levels approach or exceed this threshold.

105 dB exceeds the intelligibility threshold already established at 95 dB, making it an incorrect value for the boundary at which unintelligibility first occurs.