Yes because the watson stt node expects a single wav buffer object but straight from the mic node you get raw pcm audio chunks as a stream of buffers. So you need to join the buffers and add wav headers to it. You will need to install https://flows.nodered.org/node/node-red-contrib-wav in nodered.
Than import this flow:
[{"id":"c4303dc0.528f58","type":"Mic","z":"20693e98.c7fb2a","name":"","outputPayloadType":"buffer","endian":"little","bitwidth":"16","encoding":"signed-integer","channels":"1","device":"plughw:1,0","rate":"16000","silenceTimeout":"","exitOnSilence":"false","debug":"false","active":true,"x":350,"y":100,"wires":[["e57e38ee.a8f43","d850d294.9c4298"]]},{"id":"78a41c6d.53ef14","type":"inject","z":"20693e98.c7fb2a","name":"","topic":"","payload":"start","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":190,"y":100,"wires":[["c4303dc0.528f58"]]},{"id":"1948e4b1.02c3ab","type":"inject","z":"20693e98.c7fb2a","name":"","topic":"","payload":"stop","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":190,"y":160,"wires":[["c4303dc0.528f58"]]},{"id":"6184fc9.0b92e84","type":"join","z":"20693e98.c7fb2a","name":"","mode":"custom","build":"buffer","property":"payload","propertyType":"msg","key":"topic","joiner":"","joinerType":"str","accumulate":false,"timeout":"","count":"","reduceRight":false,"reduceExp":"","reduceInit":"","reduceInitType":"","reduceFixup":"","x":810,"y":100,"wires":[["97a658a2.a84b2"]]},{"id":"e57e38ee.a8f43","type":"switch","z":"20693e98.c7fb2a","name":"data?","property":"event","propertyType":"msg","rules":[{"t":"eq","v":"data","vt":"str"}],"checkall":"true","repair":false,"outputs":1,"x":490,"y":100,"wires":[["6184fc9.0b92e84"]]},{"id":"d850d294.9c4298","type":"switch","z":"20693e98.c7fb2a","name":"end?","property":"event","propertyType":"msg","rules":[{"t":"eq","v":"end","vt":"str"}],"checkall":"true","repair":false,"outputs":1,"x":490,"y":160,"wires":[["50230b1c.19d63c"]]},{"id":"50230b1c.19d63c","type":"change","z":"20693e98.c7fb2a","name":"complete","rules":[{"t":"delete","p":"payload","pt":"msg"},{"t":"set","p":"complete","pt":"msg","to":"true","tot":"bool"}],"action":"","property":"","from":"","to":"","reg":false,"x":640,"y":160,"wires":[["45162dad.2ec70c"]]},{"id":"45162dad.2ec70c","type":"delay","z":"20693e98.c7fb2a","name":"","pauseType":"delay","timeout":"100","timeoutUnits":"milliseconds","rate":"1","nbRateUnits":"1","rateUnits":"second","randomFirst":"1","randomLast":"5","randomUnits":"seconds","drop":false,"x":810,"y":160,"wires":[["6184fc9.0b92e84"]]},{"id":"97a658a2.a84b2","type":"wav-headers","z":"20693e98.c7fb2a","name":"","action":"add","channels":1,"samplerate":"16000","bitwidth":16,"x":990,"y":100,"wires":[["5a15fd13.012ffc"],[]]},{"id":"5a15fd13.012ffc","type":"debug","z":"20693e98.c7fb2a","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":1190,"y":100,"wires":[]}]
This will give you a single wav buffer once you stop recording. You should be able to feed this straight into the watson stt node as according to this example it accepts wav data passed in as a buffer which this is.
