Human hearing vs. frequency response

Human hearing is limited to 20kHz on the top end. So why is it important to maintain higher frequency cutoffs in equipment?

[shanecabbage]

"I'm silly today." Paul, you are silly everyday: that's why we love you. Well, aside from all of the great technical information you share. Thank you for expounding on these issues, you make technology more fun than it already is.
God bless

[marianneoelund]

*Audibility of Phase*
1. Interaural phase detection (sensitivity to phase difference between left and right ears)
"It is reasonably well established that our sensitivity to such phase locking to the TFS of stimuli is limited to frequencies below about 1500 Hz. We know this because our ability to discriminate interaural time differences (ITDs) in pure tones worsens dramatically somewhere between 1000 and 1500 Hz, and is essentially nonexistent beyond 1500 Hz (e.g., Brughera et al., 2013). Whether phase locking in the auditory nerve exists beyond that frequency limit is moot in terms of binaural processing, because it is clear that we cannot use it."


2. Harmonic phase detection
My own experiments have demonstrated no audibility of waveform changes due to harmonic phase shifts, even at fundamental frequencies as low as a few hundred hertz. In other words, it doesn't matter if harmonics above 500-1000Hz are displaced in time, because that displacement has no audible effect.

Human hearing is *not* highly sensitive to phase distortion of a signal. Its highest phase sensitivity occurs interaurally, but even there, the resolution is limited to *tens of microseconds* which corresponds to a phase shift of 45 degrees at about 4KHz. Thus a 45 degree phase shift at 20KHz is well below the audibility threshold, no matter what point of view is taken. If a 20KHz rolloff is audible, that relies on hearing the amplitude effect (-3dB) only.
In order to limit 20KHz attenuation to 1dB or less, an amplifier needs a bandwidth of 39KHz or higher, and that is the driver for extended frequency response, not phase.

[virustwin]

thanks you Paul. thanks for taking the time to pass on your knwledge

[TheGramophoneGirl]

These videos as really interesting. It wasn't until I got a decent (but vintage) hifi system that I realised the intricacies of the sound or recording and how a nice system setup brings out all the 'hidden' nuances and instruments. Tambourines that I'd never heard ever before suddenly clear as day. Sadly my vintage amp blew a few capacitors (hence finding this channel), but it is interesting to hear your advice on the various aspects of hifi. The joy of listening to a well recorded cd or vinyl through a half decent system is enlightening.

[eurgys]

Thanks Paul for those videos!!! Very good idea you started make them short.

[kenielsen]

Steen Duelund (danish speaker designer) did big research on this subjekt. There are some quite interesting articles out on the web to read about "human and hearing" ect..

[montynorth]

There is also phase shifting within passive speaker crossover units and tone controls.

[GodfreyMann]

Phase response, phase difference, phase shift, phase perfect ....brilliant, but what is ‘phase’? should’ve started with a definition....This video was incomprehensible!

[hondsvod]

Berny Sanders giving insight into audio? Subscribed!

[ericnortan]

I have a set of Sony towers I use for surround speakers. They are 3-ways with an extra "super tweeter" rated up to 50k, when I played them on my 2 channel system to give them a test drive they did have some very sweet highs.

[CraftAero]

No mention of the Fletcher Munson curve ?

[rudolfhuijs]

Meanwhile in the real world... age reduces your hearing range, among other factors like traumatisms, infections, long and constant exposure to high level noise (or music). Recently I got through an audiometry check and I only could listen between 54Hz up to 14.85kHz. I'm 53. Now I measure frequently my surrounding environment to check for average SPL below 65dB. Gone are the days when I enjoyed listening to music around 90dB and clubbing. Dr said I would be nearly deaf by 65 if neglecting my listening habits. So this 20Hz-20kHz frequency listening range is pointless to me.
Take care of your listening sense...before it's too late.

[mountainslopes]

Overhead is so important, even for longevity of the components. You don't want to be redlining a car's engine all the time and same for an amp

[ThinkingBetter]

I don’t need 3dB roll off in the treble. I need “+4dB roll on” at 12kHz due to some aging hearing loss.

[PebblesChan]

Who decided that -3dB (half power) points is used for bandwidth response limits? Shouldn’t it be just a smidgeon less than 0dB?

[usandthemx]

Paul: "The ear is sensitive to ...time alignment differences." NO ONE has heard time alignment differences, though they pretend they can.
At sea level sound moves at 745 mph. IF there is a 1.5 - 2 inch time alignment difference DO THE MATH. It can NOT be heard,
but, as I said, many PRETEND they can hear the difference! And, of course, speaker manufacturers CHARGE accordingly!

[davidhardaker]

Hello Paul, where are the P S audio speakers?

[wonderboy]

That's no ordinary thorny rose bush... but some grandaddy purple. "Feeling silly today."

[mtabernig]

Well remember you need to connect all that to a mechanical instrument called "speakers" And they cannot reproduce frequencies that high, and frequency shift on a well design amp do not happen within the designed range. So it is not a thing to worry that much unless you are dealing with testing signal generators.

[scottdc]

We can hear 20k?! Well maybe when I was in my teens.