1. Apparatus for determining a codeword in a speech coder which codes a speech signal, which speech coder determines a target signal formed in response to filtering said speech signal to remove ringing information and pitch information and which speech coder determines a linear prediction coefficient synthesis filter in response to said speech signal, said apparatus comprising: impulse response means for determining the impulse response of said synthesis filter; a first filter for filtering said target signal with said impulse response thereby forming a search signal; position locator for locating within said search signal the position of the largest positive and largest negative values; and formation means for forming a codeword comprising a series of values, wherein all values in the codeword are zero except for a first value and a second value, wherein said first value is positioned in said codeword in response to the position of said largest positive value and said second value is positioned in response to the position of said largest negative value.