|The content of Sound power level was merged into Sound power on 2011-03-22. That page now redirects here. For the contribution history and old versions of the redirected page, please see ; for the discussion at that location, see its talk page.|
|The content of Sound energy flux was merged into Sound power on 28 Mar 2015. That page now redirects here. For the contribution history and old versions of the redirected page, please see ; for the discussion at that location, see its talk page.|
|WikiProject Physics / Acoustics||(Rated Start-class, Low-importance)|
Z = c · ρ - Wrong!?
The table at Sound power with plain sound waves reads the following:
|Z = c · ρ||N·s/m³||acoustic impedance|
|ρ||kg/m3||density of air|
|c||m/s||speed of sound|
(m/s) · (kg/m3) = kg / (m2·s) != N·s/m3 (N/m2) / (m/s) = (N/m2) · (s/m) = N·s/m3
Or did I miss something?
This is correct.
Specific acoustic impedance is (not sure why the ρ is funky in the math here.
Threshold of pain?
I was wondering if on the "Sound power and sound power level of some sound sources" table, for the 120 dB row, if we could add the threshold of pain. There are various definitions for the threshold, but since 120 seems to be the most common, I think it should be included. Also, just for consistency's sake, since the auditory thresholds are included, why not include the threshold of pain? I just wanted to make sure it would be ok to add. Thanks! Hsh8 (talk) 15:23, 16 June 2009 (UTC)
- Check out the Threshold of pain article stub. It needs references! I'm not next to my bookshelf right now but I am remembering that the threshold of pain is frequency dependent, such that very, very loud low frequencies aren't as painful as very, very loud mids. Also, temporary threshold shift can occur in listeners who have been in the presence of loud sound for a little while, so that the threshold of pain can shift up to 130 dB or so for that person. Temporary threshold shifts from 5 to 20 dB have been observed, but an average value of 10 dB is present in much of the literature. Anyway, 120 dB is indeed the starting point for un-shifted listeners to experience pain.
- www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&p_id=9735 -
- Cheers - Binksternet (talk) 16:07, 16 June 2009 (UTC)
Another merge proposal
Sound power and Sound energy flux are measured in the same units (Watts) and appear to be measuring the same thing. I propose to merge Sound energy flux into this article. -—Kvng 20:06, 16 December 2012 (UTC)