Sensor working but possible unknown code error

Hi guys.
I am wondering if anyone can help me diagnose something.
I am using a feather m4 with an LSM9D51 sensor.
The code was supplied by a friend and installs fine with no issues.
The premise of the whole thing is that when there is a change in any of the 4 sensors onboard it picks a word from the database at random. I had it running for hours and no words appeared in the serial monitor panel (baud rate was correct, ruled that out)
I wondered if the sensor was faulty as the code compiled and installed just fine, so loaded the test script for the sensor, looked at it in serial monitor and its working fine, all sensors showing changes applied to them.
So, now i know the sensor is working i reloaded the code and shook, spun, gently heated and cooled the sensor......nothing, not a peep..
i recall loading this script into an uno a while back, taking out most of the words as uno is tiny in memory, and i recall it going off and showing words sporadically..
I have a schematic of the wiring layout and confirmed i have it wired up correctly.
Can anyone see why it would not show words on serial monitor or say words through the speaker?
I have an amplifier on dig pin 10, or does it need to be on analogue pin 0?
Here is the code.

#include <english.h>
#include <sound.h>
#include <TTS.h>
#include <Wire.h>
#include <SPI.h>
#include <Adafruit_LSM9DS1.h>
#include <Adafruit_Sensor.h>  

// i2c, initialize the sensor breakout board
Adafruit_LSM9DS1 lsm = Adafruit_LSM9DS1();

#define LSM9DS1_SCK 21
#define LSM9DS1_MISO 12
#define LSM9DS1_MOSI 20
#define LSM9DS1_XGCS 6
#define LSM9DS1_MCS 5

void setupSensor()
{
  // Set the magnetometer sensitivity
  lsm.setupMag(lsm.LSM9DS1_MAGGAIN_4GAUSS);
}

// Dictionary of the 1000 most common English words.
char *words[] = {"is", "it", "you", "that", "he", "was", "on", "are", "with", "as", "I", "his", "they", "be", "one", "have", "this", "from", "or", "had", "by", "hot", "word", "but", "what", "some", "we", "can", "out", "other", "were", "all", "there", "when", "up", "use", "your", "how", "said", "each", "she", "which", "do", "their", "time", "if", "will", "way", "about", "many", "then", "them", "write", "would", "like", "so", "these", "her", "long", "make", "thing", "see", "him", "two", "has", "look", "more", "day", "could", "go", "come", "did", "number", "sound", "no", "most", "people", "my", "over", "know", "water", "than", "call", "first", "who", "may", "down", "side", "been", "now", "find", "any", "new", "work", "part", "take", "get", "place", "made", "live", "where", "after", "back", "little", "only", "round", "man", "year", "came", "show", "every", "good", "me", "give", "our", "under", "name", "very", "through", "just", "form", "sentence", "great", "think", "say", "help", "low", "line", "differ", "turn", "cause", "much", "mean", "before", "move", "right", "boy", "old", "too", "same", "tell", "does", "set", "three", "want", "air", "well", "also", "play", "small", "end", "put", "home", "read", "hand", "port", "large", "spell", "add", "even", "land", "here", "must", "big", "high", "such", "follow", "act", "why", "ask", "men", "change", "went", "light", "kind", "off", "need", "house", "picture", "try", "us", "again", "animal", "point", "mother", "world", "near", "build", "self", "earth", "father", "head", "stand", "own", "page", "should", "country", "found", "answer", "school", "grow", "study", "still", "learn", "plant", "cover", "food", "sun", "four", "between", "state", "keep", "eye", "never", "last", "let", "thought", "city", "tree", "cross", "farm", "hard", "start", "might", "story", "saw", "far", "sea", "draw", "left", "late", "run", "don't", "while", "press", "close", "night", "real", "life", "few", "north", "open", "seem", "together", "next", "white", "children", "begin", "got", "walk", "example", "ease", "paper", "group", "always", "music", "those", "both", "mark", "often", "letter", "until", "mile", "river", "car", "feet", "care", "second", "book", "carry", "took", "science", "eat", "room", "friend", "began", "idea", "fish", "mountain", "stop", "once", "base", "hear", "horse", "cut", "sure", "watch", "color", "face", "wood", "main", "enough", "plain", "girl", "usual", "young", "ready", "above", "ever", "red", "list", "though", "feel", "talk", "bird", "soon", "body", "dog", "family", "direct", "pose", "leave", "song", "measure", "door", "product", "black", "short", "numeral", "class", "wind", "question", "happen", "complete", "ship", "area", "half", "rock", "order", "fire", "south", "problem", "piece", "told", "knew", "pass", "since", "top", "whole", "king", "space", "heard", "best", "hour", "better", "true", "during", "hundred", "five", "remember", "step", "early", "hold", "west", "ground", "interest", "reach", "fast", "verb", "sing", "listen", "six", "table", "travel", "less", "morning", "ten", "simple", "several", "vowel", "toward", "war", "lay", "against", "pattern", "slow", "center", "love", "person", "money", "serve", "appear", "road", "map", "rain", "rule", "govern", "pull", "cold", "notice", "voice", "unit", "power", "town", "fine", "certain", "fly", "fall", "lead", "cry", "dark", "machine", "note", "wait", "plan", "figure", "star", "box", "noun", "field", "rest", "correct", "able", "pound", "done", "beauty", "drive", "stood", "contain", "front", "teach", "week", "final", "gave", "green", "oh", "quick", "develop", "ocean", "warm", "free", "minute", "strong", "special", "mind", "behind", "clear", "tail", "produce", "fact", "street", "inch", "multiply", "nothing", "course", "stay", "wheel", "full", "force", "blue", "object", "decide", "surface", "deep", "moon", "island", "foot", "system", "busy", "test", "record", "boat", "common", "gold", "possible", "plane", "stead", "dry", "wonder", "laugh", "thousand", "ago", "ran", "check", "game", "shape", "equate", "hot", "miss", "brought", "heat", "snow", "tire", "bring", "yes", "distant", "fill", "east", "paint", "language", "among", "grand", "ball", "yet", "wave", "drop", "heart", "am", "present", "heavy", "dance", "engine", "position", "arm", "wide", "sail", "material", "size", "vary", "settle", "speak", "weight", "general", "ice", "matter", "circle", "pair", "include", "divide", "syllable", "felt", "perhaps", "pick", "sudden", "count", "square", "reason", "length", "represent", "art", "subject", "region", "energy", "hunt", "probable", "bed", "brother", "egg", "ride", "cell", "believe", "fraction", "forest", "sit", "race", "window", "store", "summer", "train", "sleep", "prove", "lone", "leg", "exercise", "wall", "catch", "mount", "wish", "sky", "board", "joy", "winter", "sat", "written", "wild", "instrument", "kept", "glass", "grass", "cow", "job", "edge", "sign", "visit", "past", "soft", "fun", "bright", "gas", "weather", "month", "million", "bear", "finish", "happy", "hope", "flower", "clothe", "strange", "gone", "jump", "baby", "eight", "village", "meet", "root", "buy", "raise", "solve", "metal", "whether", "push", "seven", "paragraph", "third", "shall", "held", "hair", "describe", "cook", "floor", "either", "result", "burn", "hill", "safe", "cat", "century", "consider", "type", "law", "bit", "coast", "copy", "phrase", "silent", "tall", "sand", "soil", "roll", "temperature", "finger", "industry", "value", "fight", "lie", "beat", "excite", "natural", "view", "sense", "ear", "else", "quite", "broke", "case", "middle", "kill", "son", "lake", "moment", "scale", "loud", "spring", "observe", "child", "straight", "consonant", "nation", "dictionary", "milk", "speed", "method", "organ", "pay", "age", "section", "dress", "cloud", "surprise", "quiet", "stone", "tiny", "climb", "cool", "design", "poor", "lot", "experiment", "bottom", "key", "iron", "single", "stick", "flat", "twenty", "skin", "smile", "crease", "hole", "trade", "melody", "trip", "office", "receive", "row", "mouth", "exact", "symbol", "die", "least", "trouble", "shout", "except", "wrote", "seed", "tone", "join", "suggest", "clean", "break", "lady", "yard", "rise", "bad", "blow", "oil", "blood", "touch", "grew", "cent", "mix", "team", "wire", "cost", "lost", "brown", "wear", "garden", "equal", "sent", "choose", "fell", "fit", "flow", "fair", "bank", "collect", "save", "control", "decimal", "gentle", "woman", "captain", "practice", "separate", "difficult", "doctor", "please", "protect", "noon", "whose", "locate", "ring", "character", "insect", "caught", "period", "indicate", "radio", "spoke", "atom", "human", "history", "effect", "electric", "expect", "crop", "modern", "element", "hit", "student", "corner", "party", "supply", "bone", "rail", "imagine", "provide", "agree", "thus", "capital", "won't", "chair", "danger", "fruit", "rich", "thick", "soldier", "process", "operate", "guess", "necessary", "sharp", "wing", "create", "neighbor", "wash", "bat", "rather", "crowd", "corn", "compare", "poem", "string", "bell", "depend", "meat", "rub", "tube", "famous", "dollar", "stream", "fear", "sight", "thin", "triangle", "planet", "hurry", "chief", "colony", "clock", "mine", "tie", "enter", "major", "fresh", "search", "send", "yellow", "gun", "allow", "print", "dead", "spot", "desert", "suit", "current", "lift", "rose", "continue", "block", "chart", "hat", "sell", "success", "company", "subtract", "event", "particular", "deal", "swim", "term", "opposite", "wife", "shoe", "shoulder", "spread", "arrange", "camp", "invent", "cotton", "born", "determine", "quart", "nine", "truck", "noise", "level", "chance", "gather", "shop", "stretch", "throw", "shine", "property", "column", "molecule", "select", "wrong", "gray", "repeat", "require", "broad", "prepare", "salt", "nose", "plural", "anger", "claim", "continent", "oxygen", "sugar", "death", "pretty", "skill", "women", "season", "solution", "magnet", "silver", "thank", "branch", "match", "suffix", "especially", "fig", "afraid", "huge", "sister", "steel", "discuss", "forward", "similar", "guide", "experience", "score", "apple", "bought", "led", "pitch", "coat", "mass", "card", "band", "rope", "slip", "win", "dream", "evening", "condition", "feed", "tool", "total", "basic", "smell", "valley", "nor", "double", "seat", "arrive", "master", "track", "parent", "shore", "division", "sheet", "substance", "favor", "connect", "post", "spend", "chord", "fat", "glad", "original", "share", "station", "dad", "bread", "charge", "proper", "bar", "offer", "segment", "slave", "duck", "instant", "market", "degree", "populate", "chick", "dear", "enemy", "reply", "drink", "occur", "support", "speech", "nature", "range", "steam", "motion", "path", "liquid", "log", "meant", "quotient", "teeth", "shell", "neck"};

// Media pins
#define PWM A0
#define buttonPin 13

TTS text2speech(PWM);  // default is digital pin 10
int buttonState = 0;
float lastMag = 0;
float lastTemp = 0;

void setup() {
  pinMode(buttonPin, INPUT);
  Serial.begin(9600);
  // Try to initialise and warn if we couldn't detect the chip
  if (!lsm.begin())
  {
    Serial.println("Oops ... unable to initialize the LSM9DS1. Check your wiring!");
    while (1);
  }
  setupSensor();
}

void loop() {
  buttonState = digitalRead(buttonPin);
  // Check if the switch has been thrown. If so, start measuring and speaking.
  if (buttonState == HIGH) {
    lsm.read();  /* ask it to read in the data */

    /* Get a new sensor event */
    sensors_event_t a, m, g, temp;

    lsm.getEvent(&a, &m, &g, &temp);
    // Get the latest magnetometer and temperature reading
    float newMag = sqrt(sq(m.magnetic.x) + sq(m.magnetic.y) + sq(m.magnetic.z));
    float newTemp = temp.temperature;
    // If this isn't our first reading...
    if (lastMag != 0) {
      // Calculate the change in magnetic field/temperature
      float deltaMag = abs(newMag - lastMag);
      float deltaTemp = abs(newTemp - lastTemp);
      // Get the biggest change of the two
      float index = max(deltaMag, deltaTemp);
      // Convert to an index of our dictionary array
      float wordindfloat = index * 1000.0;
      int wordindint = round(wordindfloat);
      // Speak the change on teh speaker
      text2speech.setPitch(6);
      text2speech.sayText(words[wordindint]);
      Serial.println(words[wordindint]);
      // Store the readings for the next loop
      lastMag = newMag;
      lastTemp = newTemp;
    }
    // Store our readings as a baseline
    else {
      lastMag = newMag;
      lastTemp = newTemp;
    }
    delay(1000);
  }
}

Get the dictionary "words" out of RAM and make sure it stays in PROGMEM.

Hi, thanks for the reply.
How do I do that?

Start here

Edit: I only saw "Uno" in your original post - I missed the "feather m4". Not sure if this will make much difference.

When I first tried this script I didn't have a feather to hand, which was the board specified, and simply ran out of room on the uno so removed most words, that seemed to work ok in serial monitor, it showed words, occasionally weird symbols. Now I'm using the same code but with all the words into the feather which has the space to take all words I'm getting nothing in serial monitor.

No, you probably simply ran out of RAM.
If you'd left the dictionary in PROGMEM, it's likely the code would have worked.

What would the code be to do that?
I think I have to add the include progmem command also?
Sorry, very very much a learner, never knew anything about progmem until you mentioned it.

Any idea why the feather is silent though, seeing as that has only used 8% of its memory on this code?

No, sorry, I don't have any of your hardware.

The reference page I linked has a lot of PROGMEM example code.

I'll have a play, see what happens.
Thanks so much for the insight.

Did you ever get this project working? I'm interested in building one myself

I THINK so, I'm not sure. I got the feather in, ran the example code, that checked out ok in serial monitor.
I put my code in, it SEEMS to be working, compiles/loads etc no issues, but I have yet to hear it speak