Of course. No sound will be the same unless one goes back to the original
source. No two printing presses will have the same sounds either. I was
concentrating on the repetitiveness and rhythm of the sounds in the sample.
On further thinking it could well be an oscillating fan as someone
suggested, very near the speaker as the voice is distorted each time which
could be the air from the fan breaking up the sound stream of the speaker.
Paul T. Jackson
Steilacoom, WA 98338
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On Jul 7, 2017 7:37 PM, "Tim Gillett" <[log in to unmask]> wrote:
> Thanks for the audio example of the press Paul. The sound of the press is
> very different from the sound on the recording in a number of ways.
> But also the voice recoding contains considerable room reverberation.
> The creaking sound does not. How likely would it be for the microphone to
> be placed right on top of such a printing press, with the interviewee on
> the distant side of the room?
> ----- Original Message ----- From: "Paul Jackson" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Saturday, July 08, 2017 6:28 AM
> Subject: Re: [ARSCLIST] Unexplained sound on oral history cassette
> Everyone has made good argumentsthat the sound is from the tape
>> processing noise. But having worked with printing machines I'm a bit more
>> inclined to believe it's a printer in the background.
>> Here is the actual sound of a Heidelberg Platen Printing Press; why I
>> think it is this in the background, perhaps behind an open door in another
>> room. http://www.workwithsounds.eu/sound/heidelberg-platen-press/
>> --Paul Jackson
>> On 7/7/2017 2:53 PM, Tim Gillett wrote:
>>> I dont think the creak sound emanates from the room but from the
>>> recorder. It carries very little room reverb so must be very close to the
>>> mic, whereas the speaker's voice carries lots of room reverb, suggesting a
>>> distant mic placement from him.
>>> The frequency of repetition of the "creak" seems roughly the same as a
>>> complete rotation of the supply tape pack around the beginning of a tape
>>> side, so perhaps a cyclic binding of the supply tape pack at each rotation.
>>> The creak sounds mechanical. It could be related to the primitive
>>> tape auto stop in many cheap cassette recorders which consisted of a small
>>> "finger" pressing onto the tape through the cassette's small window left of
>>> centre. End of the tape greatly increased back tension pushing the
>>> finger back, engaging a flywheel powered cog or cam which mechanically
>>> tripped the stop function. Often even at end of tape, the lever didnt quite
>>> fully engage into the cam or cog and instead "bounced" on it in a
>>> chattering fashion, which may be the noise we are hearing: a false or
>>> partial triggering due to the increased back tension. But the frequency of
>>> the creak seems too fast for a "one cam" type on the flywheel, The
>>> frequency of creak impulses should be much slower, or exactly the same
>>> speed as the capstan's rotation. But perhaps it wasnt a single cam but a
>>> toothed cog pressed onto the capstan shaft. I had a Sony TC
>>> The regularly varying whine seems to indicate constant "wow", which
>>> seems to correlate with an unnatural rise and fall of the speaker's voice.
>>> Hard to say if the whine is from the machine or something in the room.
>>> Around 0:40 the operator appears to move the microphone , whereby the sound
>>> of the creak disappears. Around the same time the faint whine seems also to
>>> decrease in level a little. So perhaps an external microphone was used but
>>> (at first) was placed right on the cassette recorder - a real "no, no". The
>>> loud creak sound we hear would have been much quieter for the operator who
>>> would have been much further from the source of the machine noise, but at
>>> least they heard it and appeared to have the presence of mind to move the
>>> mic from the recorder.
>>> At out State Library of Western Australia Oral History digitisation
>>> programme we encountered many cassette recordings made with internal mics
>>> or sometime external mics possibly left sitting on top of the machine.
>>> Many had so much background machine noise the voices were very hard to
>>> listen to or bordered on the unintelligible. What an improvement these days
>>> with motorless flash memory recorders!
>>> Tim Gillett
>>> Perth, Western Australia
>>> ----- Original Message ----- From: "John Chester" <[log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Saturday, July 08, 2017 3:20 AM
>>> Subject: Re: [ARSCLIST] Unexplained sound on oral history cassette
>>> The distinct midrange tone in this recording varies from about 870 to
>>>> 950 Hz. Spectrogram shows it as a series of scallops. There's a wide
>>>> curve as it drops to 870 Hz, then starts rising again. When it reaches 950
>>>> Hz, the "creak" happens, and the tone frequency starts dropping.
>>>> I think this was a cheap cassette machine, and the cassette was
>>>> jamming. I assume that playback speed was constant when this transfer was
>>>> done. If the speed was varying during recording, high tape speed during
>>>> recording = lowest tone frequency on playback, and vice-versa. When the
>>>> tone is around 870 Hz, recording speed was normal. As the tone rises in
>>>> frequency, the tape was slowing down during recording. I think the "creak"
>>>> is either mechanical noise from the cassette, picked up by a microphone
>>>> built into the recorder, or electrical noise generated by the capstan motor
>>>> governor when it freaks out because it can't rotate the capstan at the
>>>> correct speed.
>>>> Whatever the cause, it's clearly recorded on the tape. The spectrum of
>>>> the "creak" extends up to about 10 kHz. The voice sounds have a similar
>>>> upper limit. If this noise was generated during playback, it would
>>>> probably extend all the way up to 20 kHz. But I can't imagine how it could
>>>> have been generated during playback.
>>>> -- John Chester
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