help with finding characters with find()

I'am trying to build a program where I have to find all the vowels in a string.
I have managed to make this work when I check for a string where I declare a variable for example:

string phrase = "aabb eebb";

my code works perfectly and it finds four vowels, however when I changed the code to change the variable due to user input for example:

string phrase;
cin >> phrase;

and I type in the exact same string it only finds 2 vowels.
I just don't really understand the difference between the space in the string " " and the space in the input as to why I am getting two different answers. If someone could help out that would be awesome.

thanks,

anyway here is my code:

#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

int numVowels(string const, char const);

int main (int argc, char * const argv[])
{

string phrase;

cout << "Type in a phrase to search for vowels" << endl;
cin >> phrase;
int n_vowels = numVowels(phrase, 'a');
n_vowels += numVowels(phrase, 'e');
n_vowels += numVowels(phrase, 'i');
n_vowels += numVowels(phrase, 'o');
n_vowels += numVowels(phrase, 'u');
cout << "There were " << n_vowels << " vowels in your phrase." << endl;
return 0;
}

int numVowels(string phrase, char ch)
{
int vowels = 0;
size_t chFinder = phrase.find(ch, 0);
while (chFinder != string::npos)
{
vowels++;
size_t chSearch = chFinder + 1;
chFinder = phrase.find(ch, (chSearch));
}
return vowels;
}

Code:

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cin >> phrase;

---

The stream extractor >> stops reading when it finds a whitespace.
Use getline() instead.
Kurt

Thanks Kurt.