From: Christopher Woods <christof_at_infinitus.co.uk>
Date: Tue, 28 Nov 2006 11:47:26 -0000

Should Rockbox come with a PDF of a measuring tape we can use to calculate
the circumference of our heads? Because as far as I know, every person hears
sound slightly differently from the next person... Resonant frequencies
dictated by head density, width between ears and overall shape, low-end and
high-end hearing ability rolloff due to age... My Dad perceives bass louder
than I do, and I hear more treble (the acknowledged
'you're-getting-crusty-in-your-old-age' factor).

... All these stats could lead to the inclusion of a bio-, horoscope- or
(even better) a love-match calculator in Rockbox! TRULY mainstream! (if my
old Nokia's 'bonus' features were anything to go by)

> -----Original Message-----
> From: mat holton [mailto:mat_at_lessermatters.co.uk]
> Sent: 28 November 2006 10:30
> To: Rockbox development
> Subject: Re: rockbox-recorder-20061122 - volume
> representation messed up
>
> Philipp Pertermann wrote:
> > Paul Louden schrieb:
> >> In that context, 90% could actually be considered the same
> as -10%,
> >> as they're both "10% less than the full level" but since you don't
> >> have an absolute point of reference with dB, the negative numbers
> >> make perfect sense.
> >
> > Actually you do have an absolute point of reference: a full scale
> > swing of the signal. That's why it is called dbfs. But you
> are right
> > that this doesn't mean an absolute volume level as
> perceived by humean
> > ears. That is measured by db spl (sound pressure level), an
> other kind
> > of decibel. That describes the sound pressure relative to a
> sound that
> > produces a pressure change of 20uPa.
> >
> > What a pity that rockbox can not scale the volume in db spl. That's
> > impossible because it depends on the headphone and probably even on
> > how well the headphone fits into the ear.
> >
> Well, just add even more configurability. We can keep a
> database of headphone\ear types\sizes and use this
> information to calculate the necessary numbers!
>
> .
Received on 2006-11-28