Hello, Can someone explain what is meant by the "mean frequency of the voice signal"? Is this quantity important in the selection of an ADC? 3P
Mean frequency of voice signal
Started by ●November 30, 2010
Reply by ●November 30, 20102010-11-30
On 11/30/2010 02:17 PM, third_person wrote:> Hello, > > Can someone explain what is meant by the "mean frequency of the voice > signal"?Context is everything -- I think you need to at least cite where you heard the term.> Is this quantity important in the selection of an ADC?Without a definition it's hard to say. What _is_ important in the selection of an audio ADC is the quality of sound that you want to record, and the amount of money you want to spend. For telephone-quality speech you probably only need a 12 bit ADC, although a 16-bit would be nice, and you can get away with sampling at 8kHz with good enough anti-aliasing filters, although these days it's probably cheaper to sample at a higher rate and do anti-aliasing in the digital domain. For good home musical recording you're probably talking 16 bits and an excess of 44ksamples/sec. For professional audio the sky's the limit. What are you trying to do? -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" was written for you. See details at http://www.wescottdesign.com/actfes/actfes.html
Reply by ●November 30, 20102010-11-30
>On 11/30/2010 02:17 PM, third_person wrote: >> Hello, >> >> Can someone explain what is meant by the "mean frequency of the voice >> signal"? > >Context is everything -- I think you need to at least cite where you >heard the term. > >> Is this quantity important in the selection of an ADC? > >Without a definition it's hard to say. What _is_ important in the >selection of an audio ADC is the quality of sound that you want to >record, and the amount of money you want to spend. > >For telephone-quality speech you probably only need a 12 bit ADC, >although a 16-bit would be nice, and you can get away with sampling at >8kHz with good enough anti-aliasing filters, although these days it's >probably cheaper to sample at a higher rate and do anti-aliasing in the >digital domain. > >For good home musical recording you're probably talking 16 bits and an >excess of 44ksamples/sec. For professional audio the sky's the limit. > >What are you trying to do? > >-- > >Tim Wescott >Wescott Design Services >http://www.wescottdesign.com > >Do you need to implement control loops in software? >"Applied Control Theory for Embedded Systems" was written for you. >See details at http://www.wescottdesign.com/actfes/actfes.html >Thanks, Tim. I am curious, that is all. I am perplexed, actually, what can be meant by the mean frequency of voice (trivial as the average over time?). I heard the word being used in a discussion at your university. So, I'm thinking of exploring the kind of information that can be extracted from knowing the mean frequency of voice. A senior said that the mean frequency of voice is 1KHz? 3P
Reply by ●November 30, 20102010-11-30
On 11/30/2010 04:25 PM, third_person wrote:>> On 11/30/2010 02:17 PM, third_person wrote: >>> Hello, >>> >>> Can someone explain what is meant by the "mean frequency of the voice >>> signal"? >> >> Context is everything -- I think you need to at least cite where you >> heard the term. >> >>> Is this quantity important in the selection of an ADC? >> >> Without a definition it's hard to say. What _is_ important in the >> selection of an audio ADC is the quality of sound that you want to >> record, and the amount of money you want to spend. >> >> For telephone-quality speech you probably only need a 12 bit ADC, >> although a 16-bit would be nice, and you can get away with sampling at >> 8kHz with good enough anti-aliasing filters, although these days it's >> probably cheaper to sample at a higher rate and do anti-aliasing in the >> digital domain. >> >> For good home musical recording you're probably talking 16 bits and an >> excess of 44ksamples/sec. For professional audio the sky's the limit. >> >> What are you trying to do? >> >> -- >> >> Tim Wescott >> Wescott Design Services >> http://www.wescottdesign.com >> >> Do you need to implement control loops in software? >> "Applied Control Theory for Embedded Systems" was written for you. >> See details at http://www.wescottdesign.com/actfes/actfes.html >> > > Thanks, Tim. > > I am curious, that is all. > > I am perplexed, actually, what can be meant by the mean frequency of voice > (trivial as the average over time?). I heard the word being used in a > discussion at your university. > > So, I'm thinking of exploring the kind of information that can be extracted > from knowing the mean frequency of voice. A senior said that the mean > frequency of voice is 1KHz?Man I was stupid when I was a senior... I don't think that the mean frequency means much. What does mean much is how the power is distributed in a voice signal (I can't remember, but I think it's around 1kHz), and what bandwidth you need for intelligible speech (300 - 3000Hz, IIRC). That's for analog telephony -- digital cell phones compress that pretty aggressively, and for entertainment quality sound you need way more bandwidth. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" was written for you. See details at http://www.wescottdesign.com/actfes/actfes.html
Reply by ●November 30, 20102010-11-30
Tim Wescott <tim@seemywebsite.com> wrote: (someone wrote)>>>> Can someone explain what is meant by the "mean frequency of >>>> the voice signal"?(snip)> I don't think that the mean frequency means much. What does mean much > is how the power is distributed in a voice signal (I can't remember, but > I think it's around 1kHz), and what bandwidth you need for intelligible > speech (300 - 3000Hz, IIRC).Unweighted it wouldn't seem very useful, but a weighted mean, weighted by the power, could. That is, similar to center of mass being the weighted mean position of an object.> That's for analog telephony -- digital cell phones compress that pretty > aggressively, and for entertainment quality sound you need way more > bandwidth.-- glen
Reply by ●December 1, 20102010-12-01
On 11/30/2010 05:53 PM, glen herrmannsfeldt wrote:> Tim Wescott<tim@seemywebsite.com> wrote: > (someone wrote) >>>>> Can someone explain what is meant by the "mean frequency of >>>>> the voice signal"? > (snip) > >> I don't think that the mean frequency means much. What does mean much >> is how the power is distributed in a voice signal (I can't remember, but >> I think it's around 1kHz), and what bandwidth you need for intelligible >> speech (300 - 3000Hz, IIRC). > > Unweighted it wouldn't seem very useful, but a weighted mean, > weighted by the power, could. > > That is, similar to center of mass being the weighted mean > position of an object.I was thinking along those lines, but couldn't get it into words. Thanks. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" was written for you. See details at http://www.wescottdesign.com/actfes/actfes.html
Reply by ●December 1, 20102010-12-01
On Dec 1, 1:25=A0am, "third_person" <third_person@n_o_s_p_a_m.ymail.com> wrote:> >On 11/30/2010 02:17 PM, third_person wrote: > >> Hello, > > >> Can someone explain what is meant by the "mean frequency of the voice > >> signal"? > > >Context is everything -- I think you need to at least cite where you > >heard the term. > > >> Is this quantity important in the selection of an ADC? > > >Without a definition it's hard to say. =A0What _is_ important in the > >selection of an audio ADC is the quality of sound that you want to > >record, and the amount of money you want to spend. > > >For telephone-quality speech you probably only need a 12 bit ADC, > >although a 16-bit would be nice, and you can get away with sampling at > >8kHz with good enough anti-aliasing filters, although these days it's > >probably cheaper to sample at a higher rate and do anti-aliasing in the > >digital domain. > > >For good home musical recording you're probably talking 16 bits and an > >excess of 44ksamples/sec. =A0For professional audio the sky's the limit. > > >What are you trying to do? > > >-- > > >Tim Wescott > >Wescott Design Services > >http://www.wescottdesign.com > > >Do you need to implement control loops in software? > >"Applied Control Theory for Embedded Systems" was written for you. > >See details athttp://www.wescottdesign.com/actfes/actfes.html > > Thanks, Tim. > > I am curious, that is all. > > I am perplexed, actually, what can be meant by the mean frequency of voic=e> (trivial as the average over time?). I heard the word being used in a > discussion at your university. > > So, I'm thinking of exploring the kind of information that can be extract=ed> from knowing the mean frequency of voice. A senior said that the mean > frequency of voice is 1KHz?You are sure you heard the word 'mean'? It couldn't have been 'main'? Could whoever said it, have confused the two? If so, the statement is still sloppily phrased, but not quite as non-sensical as with 'mean'. Rune
Reply by ●December 1, 20102010-12-01
>On 11/30/2010 02:17 PM, third_person wrote: >> Hello, >> >> Can someone explain what is meant by the "mean frequency of the voice >> signal"? > >Context is everything -- I think you need to at least cite where you >heard the term. > >> Is this quantity important in the selection of an ADC? > >Without a definition it's hard to say. What _is_ important in the >selection of an audio ADC is the quality of sound that you want to >record, and the amount of money you want to spend. > >For telephone-quality speech you probably only need a 12 bit ADC, >although a 16-bit would be nice, and you can get away with sampling at >8kHz with good enough anti-aliasing filters, although these days it's >probably cheaper to sample at a higher rate and do anti-aliasing in the >digital domain. > >For good home musical recording you're probably talking 16 bits and an >excess of 44ksamples/sec. For professional audio the sky's the limit. > >What are you trying to do? > >-- > >Tim Wescott >Wescott Design Services >http://www.wescottdesign.com > >Do you need to implement control loops in software? >"Applied Control Theory for Embedded Systems" was written for you. >See details at http://www.wescottdesign.com/actfes/actfes.html >Thanks, Tim. I am curious, that is all. I am perplexed, actually, what can be meant by the mean frequency of voice (trivial as the average over time?). I heard the word being used in a discussion at your university. So, I'm thinking of exploring the kind of information that can be extracted from knowing the mean frequency of voice. A senior said that the mean frequency of voice is 1KHz? 3P
Reply by ●December 1, 20102010-12-01
Reply by ●December 1, 20102010-12-01
third_person wrote:> Hello, > > Can someone explain what is meant by the "mean frequency of the voice > signal"?That means nothing.> Is this quantity important in the selection of an ADC?This is equally unimportant. My dear friend, stick to what you doing and don't poke your nose into the things far beyond your comprehension. VLV
