While I’m not familiar with other Canadian jurisdictions’ requirements, it seems that the Ontario Building Code requires the use of prerecorded messages in certain circumstances. Articles 3.2.4.23 and 3.2.4.24 state the following (I’ve highlighted the relevant portions with bold text):
3.2.4.23. Two-Way Voice Communication Systems
(1) A voice communication system required by Subsection 3.2.6., Clause 3.3.2.4.(14)(f) or Sentence 3.3.4.11.(12) shall,
(a) consist of a two-way means of communication with the central alarm and control facility and with the mechanical control centre from each floor area, and
(b) be capable of broadcasting pre-recorded, synthesized or live messages from the central alarm and control facility that are audible and intelligible in all parts of the building, except in elevator cars.
(2) The voice communication system referred to in Sentence (1) shall include a means to silence the alarm signal in a single-stage fire alarm system while voice messages are being transmitted, but only after the alarm signal has initially sounded for not less than 30 s.
(3) The voice communication system referred to in Sentence (1) shall include a means to silence the alert signal and the alarm signal in a two-stage fire alarm system while voice messages are being transmitted, but only after the alert signal has initially sounded for not less than,
(a) 10 s in hospitals that have supervisory personnel on duty for twenty-four hours each day, or
(b) 30 s for all other occupancies.
(4) The voice communication system referred to in Sentence (1) shall be designed so that the alarm signal in a two-stage fire alarm system can be selectively transmitted to any zone or zones while maintaining an alert signal or selectively transmitting voice instructions to any other zone or zones in the building.
(5) The voice communication system referred to in Sentence (1) shall be designed so that visual signal devices are not interrupted while voice instructions are being transmitted.
(6) The voice communication system referred to in Sentence (1) shall be installed so that emergency communication devices are located in each floor area near exit stair shafts.
(7) A voice communication system referred to in Sentence (1) that is installed in a building that is not intended to be staffed, at times when the building will be occupied, with persons trained to provide instructions over the system shall include a pre-recorded message.3.2.4.24. One-Way Voice Communication Systems
(1) Except for Group B, Division 1 and Group F, Division 1 major occupancies, a one-way voice communication system shall be installed in a building where,
(a) a fire alarm system is required under Subsection 3.2.4.,
(b) a two-stage fire alarm system is installed, and
(c) the occupant load of the building exceeds 1 000.
(2) The voice communication system required by Sentence (1) shall consist of loudspeakers that are,
(a) operated from the central alarm and control facility or, in the absence of a central alarm and control facility, from a designated area, and
(b) designed and located so that transmitted messages are audible and intelligible in all parts of the building, except in elevator cars.
(3) A voice communication system required by Sentence (1) that is installed in a building that is not intended to be staffed, at times when the building will be occupied, with persons trained to provide instructions over loudspeakers described in Sentence (2) shall include a pre-recorded message.
(4) The voice communication system required by Sentence (1) shall meet the silencing and transmission requirements of Sentences 3.2.4.23.(2) to (5).
I regularly see voice systems in low-rise buildings in my area, and I’m starting to see voice systems in smaller installations such as event/assembly halls more frequently (this has been particularly noticeable in the last 10 years); I know of a tiny two-storey public library, for instance, that has a Mircom voice system with L-Series speaker/strobes. My personal experience with voice systems is fairly limited; I’ve only ever heard two such systems in action, and one of these used prerecorded messages.
As for federal regulations pertaining to strobes, the National Building Code of Canada acts as a model code for provinces and territories (its current requirements for visual signalling are found at article 3.2.4.19). Perhaps that provision will be updated in the future, but it will remain that individual jurisdictions will be able to make their own decisions in this regard. Its preface states the following:
The National Building Code of Canada 2020 (NBC), together with the National Plumbing Code of Canada 2020 (NPC), the National Fire Code of Canada 2020 (NFC) and the National Energy Code of Canada for Buildings 2020 (NECB), has been developed by the Canadian Commission on Building and Fire Codes (CCBFC) as an objective-based national model code that can be adopted by provincial and territorial governments.
In Canada, provincial and territorial governments have the authority to enact legislation that regulates building design and construction within their jurisdictions. This may involve the adoption of the NBC without change or with modifications to suit local needs, and the enactment of other laws and regulations regarding building design and construction, including requirements for professional involvement.
The NBC is a model code in the sense that it helps promote consistency among provincial and territorial building codes. Persons involved in the design or construction of a building should consult the provincial or territorial jurisdiction concerned to find out which building code is applicable.
Regarding the videos above, I find it interesting that both the first- and second-stage signals can be heard at the same time in the third video. I wonder why that is.