Waze does not always capture temporary reductions in speed limits, and therefore AUDIBLE speed camera alerts are based on original speed limits. Eg. on a 70mph motorway if the speed has been reduced to 50, Speed Camera alert sound is available only if you are speeding over 70. In this case if the driver is speeding above 50 but less than 70 he will not hear the speed camera alert. Alerts displayed (without sound) not always captures the attention of the driver. Hence, it is goof to include an option to have sound on for speed camera alerts irrespective of the speed. This option is available in Tom Tom.