Method and device for testing for audio induced sympathetic buzzes
CA 2136253 A1 · Owner: Madaj, David J. · Inventors: Van Hout, James E.; Kuyava, Philip A.; Madaj, David J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A pre-recorded test tape or test disk which is used to isolate unwanted buzzes in an audio listening environment. The prerecording is a series of varying amplitude frequency sweeps. The frequency sweeps from the audible range of 20Hz. to 400Hz. while the amplitude level is set at five different levels. The amplitude of the first sweep is set to the maximum output of the audio system which will give a clean 400 Hz. pre-recorded pallet tone. Each subsequent sweep is 6 dB down from the previous sweep.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed November 21, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 21, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 21, 2016.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.