According to the Canadian Intellectual Property Office website:

Trade-mark consisting of a sound

Publication Date: 2012-03-28
In view of a recent Federal Court Order, effective immediately, the Office will accept applications for sound marks.
The application for the registration of a trade-mark consisting of a sound should:
  1. state that the application is for the registration of a sound mark;
  2. contain a drawing that graphically represents the sound;
  3. contain a description of the sound; and
  4. contain an electronic recording of the sound.
Where it is not clear whether an application is intended to cover a sound mark, the Office will ask the applicant for written clarification.
Where a sound mark is considered to be functional and/or clearly descriptive or deceptively misdescriptive, an objection will be raised pursuant to the provisions of paragraph 12(1)(b) of the Trade-marks Act. In such cases, the mark may be registered pursuant to the provisions of subsection 12(2) or section 14 of the Act.

Electronic recording of sound

New applications for sound marks may only be submitted by way of a paper application, and not through CIPO’s online filing system.
The Office can only accept a recording of the sound in MP3 or WAVE format, limited to 5 megabytes in size, and recorded on a CD or DVD. Other types of recording media and references to a hyperlink or a streaming location cannot be accepted.
Electronic recordings should not contain any looping or repetition of the sound.
The electronic recording of sound should only be submitted at the time of filing, and need not be re-submitted with a revised application.