html - Center and Vertically align input fields in bootstrap -

i have set of input fields:

    <p>         <input type="image" src="images/text_to_speech.svg" alt="speak this" width="48" height="48" id="say_button"></input>          <input type="text" value="" class="input-lg" id="say_utterance" placeholder="enter text speak..."></input>          <span id="say_remaining"></span>     </p> 

it's not aligned vertically. how fix this?

for minimal code provided, it's image causing issue. add vertical-align:middle; , rest center out. demo.