SECTIONAL TRANSACTIONS .—I. 431 
Dr. A.W. G. Ewine and Dr. T.S. LirrLer.—The response of partially 
deaf patients to amplified speech at controlled intensities (11.30). 
In the investigation described speech was transmitted to a group of 
partially deaf and normal subjects through a specially designed high quality 
amplifier system set up in a sound-proof room. ‘The intensity level at 
which speech could be made most intelligible to each subject was determined 
by adjustment of an attenuator network. It was found possible to obtain 
approximately 100 per cent. intelligibility for both vowels and consonants 
with some of the partially deaf patients. 
In certain instances speech proved to be most intelligible at high levels 
of intensity involving very considerable amplification. 
With the partially deaf subjects there was found to be no apparent decrease in 
acuity after use of the apparatus for sometime. Although the peak intensity 
in the speech sounds approached the intensity that would normally produce 
fatigue in the case of a maintained pure tone, the duration of the peak 
intensities in speech sounds is small. 
The auditory acuity of each subject was measured under experimental 
conditions with pure tone stimuli produced by a beat-tone oscillator 
(a) in free air, (b) with a bone conduction receiver, and (c) when listening 
through the amplifier system. 
Mr. L. E. Heata.—Amplifiers in schools for the deaf (11.50). 
Amplification for children with residual hearing must be studied from 
three angles. ‘The teacher’s aspect involves psychology and specialised 
teaching ; the physiological aspect involves the extent and type of hearing 
defect ; the mechanical side endeavours to satisfy the requirements of the 
other two. 
The children may be classified as follows : 
(1) Those hearing all amplified speech, and understanding, or capable of 
being taught to understand it. 
(2) Those hearing only some part of it, and capable of deriving some 
benefit. 
(3) Those who will derive no benefit. 
Group (1) covers approximately 30 per cent. of the children. Groups (2) 
and (3) cannot be estimated without more research, and trials, with con- 
sideration of teaching methods, psychology of the child, and many other 
factors influencing the use of residual hearing. ‘The benefit derived may 
only be an improvement in the tone of voice, accent, rhythm or intonation 
of speech, which do not necessitate full hearing of speech. 
An ideal instrument would allow for complete control of amplification in 
standard units, and a known alteration of amplification above or below a 
known frequency. This would allow rapid adjustment of controls by 
reference to audiograms, and while avoiding harmful use of excessive 
amplification, ensure the best approach to normal conditions for each child. 
Miss E. L. S. Ross.—The psychological effects of aids to hearing (12.5). 
Main characteristics of the mental make-up of the deaf and the semi-deaf 
child, as compared with the hearing. Comparison with the blind and the 
partially sighted. Psychological effect of the special methods of education 
commonly employed. 
Report of a preliminary investigation into the psychological effect of the 
regular use of an amplifier with a group of senior children attending a school 
