Ah yes, hum and room tone, not bias. That makes sense.

Cheers,

Ellis

On Fri, Feb 26, 2016 at 5:11 PM, Ellis Burman <[log in to unmask]>
wrote:

> 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
>



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