That might be quite challenging Jamie. I had one tape where the batteries
were obviously dying - the audio sped up greatly and became distorted and
very low level towards the end of the tape. Once I speed corrected it (by
ear - just matching the voice tonality at the end with that at the
beginning, and then determining the middle part (linear? or logarithmic?),
the bias was clearly audible in the later portion of the tape. I guess the
bias frequency was very dependent on the battery voltage and dropped down
to well within audio range, even with the very slow tape speed. All I can
say is "good luck with that one" as, at least in my case, the bias
frequency was not constant.

Cheers,

Ellis

On Fri, Feb 26, 2016 at 9:26 AM, Jamie Howarth <[log in to unmask]> wrote:

> Tyra - if you want them at fixed speed we can track the hum or room tone
> and put them back in constant natural pitch. PM me at
> [log in to unmask] if you like.
>
> Jamie Howarth
> Plangent Processes
>
>
> Please pardon the mispellings and occassional insane word substitution I'm
> on an iPhone
>
> > On Feb 26, 2016, at 11:57 AM, Tom Fine <[log in to unmask]>
> wrote:
> >
> > Tyra, you could have cases where the recorder batteries were low, which
> would cause recording speed to slow down and playback speed to increase.
> I've run into that with oral histories. I usually don't even try to make
> the result "pitch perfect." Rather, I determine a point where playback
> speed has gotten so fast that the intelligability has decreased badly. I
> then go back a bit before that, and select to the end of the field. Then I
> pitch-alter it for the best overall audibility, again not worrying about
> "perfect pitch" but rather best audibility of the words being spoken. It
> depends on how fast and how clearly someone is speaking.
> >
> > -- Tom Fine
> >
> > ----- Original Message ----- From: "Grant, Tyra" <[log in to unmask]>
> > To: <[log in to unmask]>
> > Sent: Friday, February 26, 2016 11:42 AM
> > Subject: [ARSCLIST] Cassettes that speed-up---what's up?
> >
> >
> >> We're transferring a collection of personal
> cassettes---interviews---mainly from the 90s.
> >> A few start out okay then slowly speed-up so people sound like The
> Chipmunks.
> >> Then, some are okay on one side but the flip side is speeded-up.
> >> What's up here?
> >> We'd appreciate recommendations re: the best way to handle these in
> order to get something listenable.
> >>
> >> Thanks,
> >> Tyra Grant
> >> [log in to unmask]
> >> 785-864-2034
> >> University of Kansas Libraries
> >>
>



--
Ellis
[log in to unmask]
818-846-5525