I am new to iphone development.I am doing research on voice recording in iphone .I have downloaded the "speak here " sample program from Apple.I want to determine the frequency of my voice that is recorded in iphone.Please guide me .Please help me out.Thanks.
+1
A:
In the context of processing human speech, there's really no such thing as "the" frequency. The signal will be a mix of many different frequencies, so it might be more fruitful to think in terms of a spectrum, rather than a single frequency. Even if you're talking about a sustained musical note with a fixed pitch, there will be plenty of overtones and harmonics present, in addition to the fundamental frequency of the note. And for actual speech, the frequency spectrum will change drastically even within a short clip, due to the different tonal characteristics of vowels and consonants.
With that said, it does make some sense to consider the peak frequency of a voice recording. You could calculate the Fast Fourier Transform of your voice clip, then find the frequency bin with the largest response. You may also be interested in the concept of a spectrogram, which represents how the audio spectrum of a signal varies over time.
Jim Lewis
2010-03-02 18:57:16
Great response, +1
Shaggy Frog
2010-03-07 08:26:49