Talk:Loudness

From Wikipedia, the free encyclopedia

WikiProject Physics This article is within the scope of WikiProject Physics, which collaborates on articles related to physics.
Stub This article has been rated as Stub-Class on the assessment scale.
??? This article has not yet received an importance rating within physics.

Help with this template This article has been rated but has no comments. If appropriate, please review the article and leave comments here to identify the strengths and weaknesses of the article and what work it will need.
This article has been automatically assessed as Stub-Class by WikiProject Physics because it uses a stub template.
  • If you agree with the assessment, please remove {{Physics}}'s auto=yes parameter from this talk page.
  • If you disagree with the assessment, please change it by editing the class parameter of the {{Physics}} template, removing {{Physics}}'s auto=yes parameter from this talk page, and removing the stub template from the article.

The article List of heavy metal musicians should have a wikilink to here, but sadly i don't know LOUDNESS and don't know to which subdivision of metal it should be caunted, so i can't add it. Please do so if you feel competent about it. Lady Tenar 23:10, 1 Mar 2004 (UTC)

[edit] Loudness and speed of sound

Does the loudness of a wave affect the speed of a wave? What factors affect the speed of sound? freestylefrappe 01:54, August 7, 2005 (UTC)

I'm not sure I understand your question correctly but in your average airspace sound always travels at the same speed. The Speed of sound is defined by the medium it travels through (air, water etc.) and is slightly modified by temperature.
On the other hand if you're talking about speed as the rate of a wave signal then you should see frequency for more details. The frequency of a sound defines it's pitch. Frequency is not modifed by loudness and neither is the speed of a sound. Loudness modifes velocity of a sound. --Mattimatti 06:21, 11 August 2006 (UTC)
Loudness is primarily a correlate to the amplitude of a sound. The speed of a sound is defined only by the properties of the medium it travels within and not the amplitude nor frequency. The Sleepwalker 22:02, 8 January 2007 (UTC)

[edit] Scavenged from deletions

Could be incorporated somehow!

Auditory Physiology

Louder sounds have less spatial selectivity on the basilar membrane (chochlea in the inner ear), weaker sounds are more restricted localized. Loudness is heard at the shallow end of the envelope triangle of a traveling wave (sound). Frequency discrimination is performed at the end. The number of activated nerve fibers used per inner hair cell increases with the stimulus intensity. Auditory fibers with identical best frequencies have different response thresholds.

--Light current 21:54, 23 June 2006 (UTC)

[edit] Is Sound Energy/Power a function of Sound Frequency ? Why ?

When you look at the frequency spectrum of a song, with a linear frequency axis scale, the low frequencies appear much stronger (even in dB) than the high frequencies. Why is that? Is it inherent to the properties of sound itself, or does it reflect our ears' relative sensitivity to high frequency sound and the sound engineers therefore adjusted the spectrum so we may hear low frequencies as loud as high frequencies (i.e. they intentionally made low frequencies louder because our ears are relatively insensitive to them)? —The preceding unsigned comment was added by 82.227.97.30 (talk) 07:26, 7 January 2007 (UTC).

Hearing actually quite clearly functions on a logarithmic frequency scale (see the tonotopic nature and arrangement of the basilar membrane and auditory nerve). If you look at distribution of energy on a log scale, it tends to be relatively flat. Flat energy on a logarithmic scale equals an even distribution across the auditory system. The Sleepwalker 21:59, 8 January 2007 (UTC)

The mentioned lower power spectral density at higher frequencies is also a natural result of harmonic frequencies as seen by sinusoidal decomposition of musical notes (Fourier series). The fundamental tone is the lowest frequency and defines the "note" being played. The Timbre is given by the relative intensities of all the harmonics present (fundamental and overtones). There are rare examples of missing fundamentals (e.g. bassoon, I believe), but by far the most common type of spectrum is of decreasing amplitude for higher overtones. Usually, any resonant structure (stretched string, resonant air-cavity or vibrating bar, typically) will respond most at its fundamental frequency, and have smaller resonant peaks at all integer multiples of it. On a logarithmic frequency scale (closer to human perception), the reduced amplitude higher harmonics bunch up, so, as The Sleepwalker says, the distribution is much flatter for most music when represented this way. White noise and transient impulses (especially as they get very short, approaching the Dirac delta function) have a flat spectrum on the linear frequency scale, however, so identifying percussive impacts is often easiest on a linear-frequency spectrogram, where they are represented by a bright vertical line of a single colour (=intensity) when shown in the most common spectral display format used in audio software. Constant background hiss (white noise), is typically a single colour representing low intensity. --Dynamicimanyd 09:03, 13 August 2007 (UTC)