In summary, the IEC60601-1-8 standard for medical electrical equipment has established requirements for audible alarms for use in medical equipment. Four main requirements were discussed in this module. The first requirement is that the fundamental frequency of the alarm tone must be between 150Hz and 1kHz. Second is the requirement that there must be at least four harmonic peaks between 300Hz and 4kHz, and the third requirement is that the sound pressure level of these harmonic peaks must be within ±15dB of the fundamental. Finally, the fourth requirement is that the alarm device must be capable of producing three specific priority sounds; high priority is a train of ten quick beeps that repeat, medium priority is a group of three slower beeps that repeat, and the low priority signal is two slow beeps that may or may not repeat. Mallory Sonalert produces four devices that are compliant with IEC60601-1-8. Three of the devices, models MSS300R, SCS300MDB, and SCS300MDS are passive, with no internal circuitry, while the MSS5M1 is an active unit with internal sound generating circuitry. The passive devices require that the user supply a 325Hz square wave signal with the specified timing for the desired priority sequence; while the MSS5M1 requires only the application of a +5Vdc supply and ground on the appropriate control pin(s) to select the desired priority sound to be output.