TranscribeAudioText.cmp

<aura:component controller="GoogleSpeechService" implements="lightning:isUrlAddressable,force:appHostable,flexipage:availableForAllPageTypes,flexipage:availableForRecordHome,force:hasRecordId,forceCommunity:availableForAllPageTypes,force:lightningQuickAction" access="global" >
  	<aura:attribute name="recordId" type="String"/>
   	<lightning:card title="Google Transcription">
    	<lightning:button variant="brand" label="Convert Audio to Text" title="Convert Audio to Text" onclick="{! c.translate }" />
        <lightning:textarea name="translatedText" label="" value="Transcript Placeholder" />
    </lightning:card>
</aura:component>

TranscribeAudioTextController.js

({
	 translate : function(component, event, helper) {
        var recordId = component.get('v.recordId');
        var action  = component.get("c.GetTranscript");
        action.setParams({
            "recordid": recordId
        });
        action.setCallback(this, function(response){
            var status = response.getState();
            if(status === "SUCCESS"){
                var responseCode = response.getReturnValue();
                alert(JSON.stringify(responseCode));
                
                var result=responseCode.result;
                var textVal='';
                for (i = 0; i < result.alternatives.length; i++) {
                    textVal += result.alternatives[i];
                }
                alert(textVal);
               
            }
        });
        
        $A.enqueueAction(action);
    }
})