Five Semitone Difference
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@George-K I've been that far out on alto sax and nobody seemed to care.
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@Mik said in Five Semitone Difference:
Why would you ever do that?
(I'm so old that I remember the days before pulse oximeters)
Nevertheless, after years and years of listening to the "beep" you get a certain frequency into your head. Anything significantly away from that usually means bad things.
Apparently there's quite a lot of variability:
Recordings containing 509 to 1053 pulse tones were made from the 21 pulse oximeters. Fundamental frequencies at 100% saturation ranged from 479 to 921 Hz, and fundamental frequencies at 1% saturation ranged from 38 to 404 Hz. The pulse tones from all but one model pulse oximeter contained harmonics. Pulse tone step sizes were linear in 6 models and logarithmic in 6 models. Only 6 pulse oximeter models decreased the pulse tone pitch at every decrease in saturation; all others decreased the pitch at only select saturation thresholds. Five pulse oximeter models stopped decreasing pitch altogether once the saturation reached a certain lower threshold. Pulse tone power (perceived as loudness) changed with saturation level for all pulse oximeters, increasing above baseline as saturation decreased from 100% and decreasing to levels below baseline at low saturation values.
Since we always bought from the same company, I was unaware of how different the tones could be.
