jump to navigation

What is the frequency response of the North American Public Switched Telephone Network? June 3, 2009

Posted by HubTechInsider in Telecommunications, VoIP, VUI Voice User Interface, Wireless Applications.
Tags: , , , , , , ,
trackback
Sinusoidal waves of various frequencies; the b...

Image via Wikipedia

The conventional North American Public Switched Telephone Network, or PSTN, has a frequency response range of 300 Hz to 3,400 Hz. The normal hearing range of humans is typically 30 Hz to 20,000 Hz. So the conventional telephone transmission system is unable to carry bright, high-frequency and deep, low-frequency tones.

But, somewhat surprisingly, because our ears are so used to hearing poor-quality audio over the telephone, our brains actually “fill in” the missing frequencies. As an example, the crisp “s” sound in the word “Christmas”. So in effect, the telephone audio often sounds better than it actually is to us.

Comments»

1. excelandaccess - February 27, 2012

Really, that is amazing, I did not know that. I use a JawBone with my iPhone, and rarely use the phone itself. And when in online meetings I wear a Logitech headset, which is much clearer than the Jawbone.

We do not have a landline, so no comment there.

Nice post. Interesting topic.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 26,753 other followers

%d bloggers like this: