Question

What is a pitch (in sound)?

It is related to the frequency i.e. if more frequency more pitch and vice versa.
so when we talk, if we speak speedily then more frequency but if we speak slowly then low frequency? right or wrong? then how do we know that his voice has high frequency (or pitch) than the other?

Answer 1

Pitch relates to how high or low the sound is, which in turn depends on the frequency of the vibration

Explanation:

Pitch is nothing to do with 'speed of speaking' as you suggest above. It is to do with the number of waves that are 'packed' into the sound - the more waves or cycles per second, the higher the frequency and therefore the higher the pitch. So a higher pitched tuning fork will vibrate faster (and this is where speed does com into it) i.e. there are more vibrations or waves per second. The musical note (middle) 'A' for instance, corresponds to a frequency of 440Hz, or 440 full vibrations per second.

Answer 2

Pitch in sound is frequency

Explanation:

The speed of speaking is not related to frequency though. If you consider someone with a deep voice (low frequency, low pitch), they can be speaking slowly or quickly, but their pitch can be the same. Equally, a person with a high pitch voce (high frequency) can speak slowly, but they will still have a high pitch voice.

Our ear enable us to identify high and low pitch