WD25T and fire surrounds

[Graham Wright]

Originally Posted by bob orbell

Graham, are you saying that you can not hear much above 800 Hz or below 800 Hz, I think most on here can hear around 20 - 15000 Hz, may be even higher or lower, I feel for you chap. BOB

Measles apparently.

Ok up to 800Hz (in fact enhanced, possibly subjectively) with low frequency thumps. Up till recently, wife could hear bats!

I'm waiting for the stem cells!

[Graham Wright]

I like the idea of removable covers although whether it would make any difference to me I don't know (and SWMBO doesn't do hifi - "It's too loud!").

I'm tending towards some dark gold fabric with fancy mahogany overlays. Ours is a modern room so the Victorian et al ebay offers are not representative.

[andrew ivimey]

'...I think most on here can hear around 20 - 15000 Hz...'

That's an interesting assertion Bob. How do you derive this?

[bob orbell]

OK Andrew, of course I have no evidence of my statement, but I was amazed and very surprised that some one could go to a lot of trouble to get his kit sounding good and only hear up to 800 Hz, I have a signal gen. and I can hear up to and beyond 15000, as for the lows, my speakers roll off at about 32 Hz which I can hear. As I said, I feel most on the forum can hear those frequency's, I hope that I am correct and have pity on Mr Walker. BOB

[Graham Wright]

Originally Posted by bob orbell

OK Andrew, of course I have no evidence of my statement, but I was amazed and very surprised that some one could go to a lot of trouble to get his kit sounding good and only hear up to 800 Hz, I have a signal gen. and I can hear up to and beyond 15000, as for the lows, my speakers roll off at about 32 Hz which I can hear. As I said, I feel most on the forum can hear those frequency's, I hope that I am correct and have pity on Mr Wright. BOB

Others listen to these speakers as well!

I play the piano and the top couple of octaves sound just like clunks! I also play the organ but the subharmonics help out.

I have volunteered as a guinea pig for Sheffield University (which seems to be a centre of excellence in stem cell research) but my offer was spurned (by the local hospital not Sheffield).

[andrew ivimey]

Fine, so relative to say 1kHz OR 2kHz how well can you hear 15kHz? This measurement is crucial because the experience of a 15kHz pure tone (and we are talking here of a sine wave) at 30dBSPL is very different to the experience of the same frequency sine wave at 130dBSPL.

(Also, how well calibrated is your sine wave generator, your amp system and your speakers? - you could be hearing intermodulation distortion!)

Graham said that he has hearing up to 800Hz and then an almost total cut off. This is possible but rare. I would like to know more but not perhaps in so public a place.

If what Graham said is correct about his hearing I still don't see a problem with him setting out and striving to build a super system that presses his buttons, so to speak, even if he really doesn't have to worry about sound over, oooooo, 8kHz. My father's hearing could now be said to be similar to how Graham describes his hearing except that it is worse below 800Hz too! (50dB down at 250Hz, bi-laterally) He wears powerful hearing aids, which no longer help his perception of music. He is very articulate about what he can and cannot hear. Yet he listens to a great deal of opera and derives much pleasure - How? Why? To cut a very long story short - auditory memory! He has been a practising musician all his life, a fine pianist and his dad was a conductor (albeit in the army). When my dad looks at a musical score (even with his macular degeneration and several strokes) he can hear the music. A wretched hearing loss isn't going to put him off!

Back to the central issue - I would expect that anyone who has gone through life listening to loud music and/or been exposed to high levels of noise, industry or the military and started off with 'normal hearing' would, in their fifties, begin to have a hearing loss in the high frequencies. Our hearing wears out as do all other parts of our bodies and it is always the high frequencies we lose first, for basic physiological reasons. I wonder, are we all old ( i.e. over 50...60...70) codgers hereabouts given to listening to LedZep and Shostakovich dead loud ?!)

Apologies to the forum for the hi-jack!

[pre65]

Thanks Andrew, for an interesting and informative article.

For those who don't know, Andrew is an Audiologist by profession.

[Graham Wright]

Originally Posted by andrew ivimey

Fine, so relative to say 1kHz OR 2kHz how well can you hear 15kHz? This measurement is crucial because the experience of a 15kHz pure tone (and we are talking here of a sine wave) at 30dBSPL is very different to the experience of the same frequency sine wave at 130dBSPL.

(Also, how well calibrated is your sine wave generator, your amp system and your speakers? - you could be hearing intermodulation distortion!)

Graham said that he has hearing up to 800Hz and then an almost total cut off. This is possible but rare. I would like to know more but not perhaps in so public a place.

My hearing acuity was assessed in a hospital auditory department. At 800Hz,
the drop off was cliff like! I saw the graph.

Iw measles wot dun it!

[Graham Wright]

Originally Posted by andrew ivimey

Fine, so relative to say 1kHz OR 2kHz how well can you hear 15kHz? This measurement is crucial because the experience of a 15kHz pure tone (and we are talking here of a sine wave) at 30dBSPL is very different to the experience of the same frequency sine wave at 130dBSPL.

(Also, how well calibrated is your sine wave generator, your amp system and your speakers? - you could be hearing intermodulation distortion!)

Graham said that he has hearing up to 800Hz and then an almost total cut off. This is possible but rare. I would like to know more but not perhaps in so public a place.

The 800Hz cut-off was the result of auditory assessment. I saw the graph and there was hardly any roll off.

[andrew ivimey]

As an adult?

Measles is a buggar - you have my sympathy.

So many viruses are relatively harmless to most people if they come in childhood. Measles and mumps, for example, can do so much more damage when one is an adult!