Home Appliance Noise: Annoyance and Speech Interference

How annoying is appliance noise? How much does appliance noise interfere with speech? While listening to the noise from 10 different home appliances, eight subjects wrote the words being read to them. Then they voted their annoyance with each noise on a 5-point scale. Annoyance score was well described by a straight line as a function of decibels on the A scale (dbA). Speech interference in percentage of words missed also was well predicted by a straight line where percentage missed was a function of dbA.