Subject: Re: decibel comparison chart - verbal description of 37 dbA From: Adam Weisser <adam_weisser@xxxxxxxx> Date: Thu, 15 Jan 2026 19:08:36 +0200--109a3879746947d5b4025435a1765cca Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Dear Nuno and all, I think you're right that there may not be such a chart from an independent= source, unless there is either an old one or a very recent one that I'm un= aware of. As part of our work on the ARTE database (Buchholz & Weisser, 201= 8), we reviewed all the available noise-level databases we could find (up t= ill 2018) and you can find several useful references there (Weisser et al, = 2019), beginning with the seminal report by Pearsons et al (1977) on indoor= speech and noise levels. Some of the sampled indoor noise levels in the "h= ome" category were within the 35 - 40 dBA range (see Figure 6 in Peasons et= al).=20 In general, the within-category variance in reported measurements as the ab= ove seems to be large. Therefore, even if a given quiet apartment or classr= oom measured 37 dBA background noise level, it could be difficult to genera= lize it to arbitrary environments, because individual sounds could easily d= ominate the total noise level when it is so low. For example, the quietest = environment we reported in ARTE was a university library (46 dBA; Table I, = Weisser et al. 2019). We attempted to list all the sound objects that could= be confidently identified during the two-minute duration of that recording= , which turned out to be a rather specific list of low-level sounds (Weisse= r, 2018, Figure 5.3). This is in contrast with the noisiest environments we= recorded that were dominated by fewer and nondescript sound types (Ibid, f= igure 5.4).=20 Best, Adam. Buchholz, J. M., & Weisser, A. (2019). *Ambisonics recordings of typical en= vironments (ARTE) database*. https://urldefense.com/v3/__https://zenodo.org= /record/3386569__;!!BDUfV1Et5lrpZQ!XfHllE8Svtvd5uz-JmF6nfTpdzWHO7EzYZhXwaSa= ENY4hIF-vqI26fAVYKh7uOs1wPnALdYg2AWMbqjeAEbQp_-025mQ$=20 Pearsons, Karl S, Bennett, Ricarda L., Fidell, Sanford:* Speech levels in v= arious noise environments*. Technical Report EPA600/1-77-025, O=EF=AC=83ce = of Health and Ecological Effects, O=EF=AC=83ce of Research and Development,= US EPA, May 1977. Weisser, A. *Complex Acoustic Environments: Concepts, Methods, and Auditory= Perception*. PhD thesis, Macquarie University, 2018. Weisser, A., Buchholz, J. M., Oreinos, C., Badajoz-Davila, J., Galloway, J.= , Beechey, T., & Keidser, G. (2019). *The Ambisonic Recordings of Typical E= nvironments (ARTE) database*. *Acta Acustica united with Acustica*, *105*(4= ), 695-713. On Wed, Jan 14, 2026, at 8:53 AM, Nuno Diniz wrote: > Hi all, >=20 > I've searched for decibel comparison tables online but failed to get a "r= eliable" one that is not from a company or some random site. Could you prov= ide me with some from a university, acoustic department/institution, etc ..= ? >=20 > Also, for a current project, how would you describe a value of 37 dbA or = LAeq? >=20 > Many thanks in advance > Best regards > Dr. ir. Nuno Diniz Adam Weisser, PhD https://urldefense.com/v3/__https://hearingtheory.org/__;!!BDUfV1Et5lrpZQ!X= fHllE8Svtvd5uz-JmF6nfTpdzWHO7EzYZhXwaSaENY4hIF-vqI26fAVYKh7uOs1wPnALdYg2AWM= bqjeAEbQp-wPwlDc$=20 --109a3879746947d5b4025435a1765cca Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable <!DOCTYPE html><html><head><title></title></head><body><div style=3D"font-f= amily:Arial;">Dear Nuno and all,</div><div type=3D"cite" id=3D"qt" style=3D= ""><div style=3D"font-family:Arial;"><br></div><div style=3D"font-family:Ar= ial;">I think you're right that there may not be such a chart from an indep= endent source, unless there is either an old one or a very recent one that = I'm unaware of. As part of our work on the ARTE database (Buchholz & We= isser, 2018), we reviewed all the available noise-level databases we could = find (up till 2018) and you can find several useful references there (Weiss= er et al, 2019), beginning with the seminal report by Pearsons et al (1977)= on indoor speech and noise levels. Some of the sampled indoor noise levels= in the "home" category were within the 35 - 40 dBA range (see Figure 6 in = Peasons et al). </div><div style=3D"font-family:Arial;"><br></div><div= style=3D"font-family:Arial;">In general, the within-category variance in r= eported measurements as the above seems to be large. Therefore, even if a g= iven quiet apartment or classroom measured 37 dBA background noise level, i= t could be difficult to generalize it to arbitrary environments, because in= dividual sounds could easily dominate the total noise level when it is so l= ow. For example, the quietest environment we reported in ARTE was a univers= ity library (46 dBA; Table I, Weisser et al. 2019). We attempted to list al= l the sound objects that could be confidently identified during the two-min= ute duration of that recording, which turned out to be a rather specific li= st of low-level sounds (Weisser, 2018, Figure 5.3). This is in contrast wit= h the noisiest environments we recorded that were dominated by fewer and no= ndescript sound types (Ibid, figure 5.4). </div><div style=3D"font-fam= ily:Arial;"><br></div><div style=3D"font-family:Arial;"><div style=3D"font-= family:Arial;">Best,</div><div style=3D"font-family:Arial;">Adam.</div><div= style=3D"font-family:Arial;"><br></div></div></div><div style=3D"font-fami= ly:Arial;">Buchholz, J. M., & Weisser, A. (2019). <i>Ambisonics recordi= ngs of typical environments (ARTE) database</i>. <a href=3D"https://ur= ldefense.com/v3/__https://zenodo.org/record/3386569__;!!BDUfV1Et5lrpZQ!XfHl= lE8Svtvd5uz-JmF6nfTpdzWHO7EzYZhXwaSaENY4hIF-vqI26fAVYKh7uOs1wPnALdYg2AWMbqj= eAEbQp_-025mQ$">https://zenodo.org/record/3386569</a><br></div><div style= =3D"font-family:Arial;"><br></div><div type=3D"cite" id=3D"qt" style=3D""><= div style=3D"font-family:Arial;"><div>Pearsons, Karl S, Bennett, Ricarda L.= , Fidell, Sanford:<i> Speech levels in various noise environments</i>. Tech= nical Report EPA600/1-77-025, O=EF=AC=83ce of Health and Ecological Effects= , O=EF=AC=83ce of Research and Development, US EPA, May 1977.</div><div><br= ></div></div><div style=3D"font-family:Arial;">Weisser, A. <i>Complex Acous= tic Environments: Concepts, Methods, and Auditory Perception</i>. PhD thesi= s, Macquarie University, 2018.</div><div style=3D"font-family:Arial;"><br><= /div><div style=3D"font-family:Arial;">Weisser, A., Buchholz, J. M., Oreino= s, C., Badajoz-Davila, J., Galloway, J., Beechey, T., & Keidser, G.=20 (2019). <i>The Ambisonic Recordings of Typical Environments (ARTE)=20 database</i>. <i>Acta Acustica united with Acustica</i>, <i>105</i>(4), 695= -713.</div><div style=3D"font-family:Arial;"><br></div><div style=3D"font-f= amily:Arial;"><br></div><div>On Wed, Jan 14, 2026, at 8:53 AM, Nuno Diniz w= rote:</div><blockquote type=3D"cite" id=3D"qt-qt" style=3D""><div dir=3D"lt= r"><div>Hi all,</div><div><br></div><div>I've searched for decibel com= parison tables online but failed to get a "reliable" one that is not f= rom a company or some random site. Could you provide me with some from a un= iversity, acoustic department/institution, etc .. ?</div><div><br></div><di= v>Also, for a current project, how would you describe a value of 37 dbA or = LAeq?</div><div><br></div><div>Many thanks in advance</div><div>Best regard= s</div><div>Dr. ir. Nuno Diniz</div></div></blockquote><div style=3D"font-f= amily:Arial;"><br></div><div id=3D"qt-sig118869776"><div class=3D"qt-signat= ure">Adam Weisser, PhD</div><div class=3D"qt-signature"><a href=3D"https://= urldefense.com/v3/__https://hearingtheory.org/__;!!BDUfV1Et5lrpZQ!XfHllE8Sv= tvd5uz-JmF6nfTpdzWHO7EzYZhXwaSaENY4hIF-vqI26fAVYKh7uOs1wPnALdYg2AWMbqjeAEbQ= p-wPwlDc$">https://hearingtheory.org/</a></div><div class=3D"qt-signature">= <br></div></div><div style=3D"font-family:Arial;"><br></div></div><div styl= e=3D"font-family:Arial;"><br></div><div style=3D"font-family:Arial;"><br></= div></body></html>= --109a3879746947d5b4025435a1765cca--