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Re: [AUDITORY] A question about calibration of very high frequencies



Dear Sylvie,

I also wondered what you meant by "exceptionally high"? Is that that in previous measures you didn't have this noise? Or is it that it is high in absolute terms (what are the numbers then)?

High frequency noise can come from fans, neon lights, screens... Although the latter two tend to have narrow spectra. Faulty preamp on our sound level meter has also displayed HF noise in the past.

-Etienne


On Fri, 31 May 2019, 06:09 Bernstein,Leslie, <lbernstein@xxxxxxxx> wrote:
Hello--

In order to help, much more information is required:

Exactly what equipment is it that you wish to calibrate?
What equipment are you using or do you have available to make the measures of the desired signal and the associated noise floor?

There are quite a few explanations for what you have found that can be narrowed down based on the answers to the questions above.  Given reasonable assumptions of linearity and availability of precision attenuators, it is often not necessary at all to make such measures at low levels.  Whether that's true in your case will depend upon the details.

Les


On 5/30/2019 12:18 AM, Hébert Sylvie wrote:

Dear List,


We would like to calibrate our equipment to verify that it is capable to sending low-intensity narrowband noises just above auditory threshold. We have found that the baseline noise levels were exceptionally high for band frequencies above 8kHz. Can anyone explain why this may be the case? Does anyone have any suggestions for how to approach measuring very low-intensity sounds?

 

Thanks,


Sylvie Hébert, Ph.D., Professor

School of Speech pathology and audiology

Pavillon 7077, Parc ave. -  3rd floor  -   room 3001-34

Faculty of medicine  | Université de Montréal

Université de Montréal


Address : c.p. 6128, succ. Centre-ville, Montréal, 

H3C 3J7 Tel: (514) 343-6111 #2594

www.eoa.umontreal.ca

 

 

Regular member

International laboratory for Brain, Music, and Sound Research (BRAMS)

Center for Research on Brain, Language, and Music



--
Leslie R. Bernstein, Ph.D. | Professor
Depts. of Neuroscience and Surgery (Otolaryngology)| UConn School of Medicine

263 Farmington Avenue, Farmington, CT 06030-3401
Office: 860.679.4622 | Fax: 860.679.2495


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