The following is a discussion of Halachic topics related to the Parsha of the week.
For final rulings, consult your Rav.
He heard the voice speaking to him (7:89)
Amplified Sound Waves
Can one fulfill a mitzvah which involves hearing something recited
or read, e.g., hearing Havdalah or the reading of Megillas Esther, by
hearing the words over a telephone or from the loudspeaker of a public
The answer to this question, extensively debated by the poskim,
depends on the halachic interpretation of certain technical facts. Both the
telephone and the public address system "transform" sound waves in air,
e.g., spoken words, into an electrical current within the instrument, and,
ultimately, back into sound waves.
It is debatable, though, how the halachah
views these sound waves:
Are they an extension of the speaker's voice,
merely amplified or carried to a distance that the unassisted human voice
cannot reach; or are they distinct from the speaker's voice, since the
loudspeaker or receiver "creates" new sound waves from something--an
electrical current, which is not sound?
Translated from technical into halachic terms, the question is whether the
mitzvah in question can be fulfilled only with the authentic, original voice
of the speaker, or also by means of sounds generated by electrical impulses
derived from the original voice and occurring simultaneously with it.
Some earlier authorities (1) were of the opinion that the sound heard over
the telephone or from the loudspeaker is the original speaker's voice. It is
permitted, therefore, in their opinion (2) to listen to the megillah read
over a public address system or to Havdalah over the telephone.
Other authorities (3) maintained that the halachic view of amplified sounds
is difficult to resolve and cannot be clearly decided. Thus in their opinion
it remains questionable if mitzvos can be performed by means of a public
address system or telephone. It follows, therefore, that only under
extenuating circumstances--when no other possibility exists--is it
permitted to fulfill a mitzvah by means of a loudspeaker or telephone (4).
However, the majority of the authorities (5) who have studied this issue,
including Harav S.Z. Auerbach (6) who researched it extensively with the aid
of a team of technical experts (7), have ruled conclusively that the sound
waves emitted by a loudspeaker or telephone receiver are definitely not the
speaker's original, authentic voice. In addition, they rule unequivocally
that one's obligation cannot be discharged by hearing an electrically
generated sound even if the original speaker's voice is heard
simultaneously. Accordingly, one cannot, under any circumstances, fulfill a
mitzvah by listening to sound waves from a microphone or a telephone (8).
In practice, therefore, it is clear that when another possibility exists,
mechanical voice amplifiers should not be used to fulfill a mitzvah. For
example, a woman who is home alone and has no one to make Havdalah for her,
should rather recite Havdalah herself (9) than listen to it being recited by
someone else over the telephone. Even if she cannot or will not drink wine,
grape juice, or beer, it is better for her to recite Havdalah over
coffee (10), tea [with or without milk] (11), or milk alone (12) [and,
according to some poskim (13), grapefruit, orange or apple juice] than to
listen to Havdalah recited over the phone (14).
If one finds himself in a situation where otherwise he cannot recite
Havdalah or hear the megillah at all, e.g. in a hospital, and there is no
one who can come until Tuesday evening (15) to make Havdalah for him, he may
have to rely on the poskim who permit listening to blessings, etc., over the
telephone (16). But in a situation where someone could come and recite
Havdalah for him before Tuesday evening, the correct procedure is to wait
until then for Havdalah to be recited (17). If he is weak, he may eat before
hearing Havdalah. If he is not, he should not eat until Sunday at
A related issue is whether or not it is permitted to answer amen to a
blessing or Kaddish heard over a microphone, telephone, or during a live
telecast transmitted by satellite. Some poskim (19) permit this and do not
consider the answering of amen etc., to be l'vatalah ("for nothing"), since
they remain undecided about the halachic status of amplified sound waves, as
explained above. In addition, some poskim (20) permit it, based on the
ancient precedent set in the great synagogue in Alexandria (21), where most
people did not hear the blessings being recited because of its vast size,
but were nevertheless permitted to answer amen when signaled to do so by the
waving of a flag.
Harav Auerbach, though, rejects this comparison and rules clearly that it
is prohibited to answer amen upon hearing a blessing in this manner. He
agrees, however, that one who is in the vicinity of the speaker, even though
he hears the speaker's voice only over a microphone, etc., is permitted to
answer amen, as was the case in Alexandria where everyone was inside the
shul and part of the tzibbur that was davening.
2 Their argument is based partially on the fact that sound waves--even
without being mechanically transmitted--are carried through the air before
they are heard by the listener. The fact that the microphone amplifies those
sounds and furthers their distance should not be considered halachically
3 Harav T. P. Frank (Mikraei Kodesh, Purim 11 and in Minchas Yitzchak
2:113); Igros Moshe O.C. 2:108; O.C. 4:126. [See, however, Igros Moshe E.H.
1:33 and O.C. 4:84.] Harav Y.Y. Henkin (Eidus l'Yisrael, pg. 122) also does
not render a clear decision on this issue. See also Minchas Shelomo 9
quoting an oral conversation with the Chazon Ish.
4 Tzitz Eliezer 8:11. See also Shevet ha-Levi 5:84.
5 Da'as Torah O.C. 689:2; Gilyonei ha-Shas, Berachos 25a; Eretz Tzvi 1:23;
Kol Mevaser 2:25; Mishpatei Uziel 1:5; Minchas Yitzchak 1:37, 3:38; She'arim
Metzuyanim b'Halachah 129:25; 193:6; Kinyan Torah 1:75; Yechaveh Da'as 3:54;
Moadim u'Zemanim 6:105. See also Teshuvos P'eas Sadcha 126 who quotes such a
ruling from Reb Chayim Soloveitchik.
6 Minchas Shelomo 9.
7 Harav Auerbach and Yechaveh Da'as add that those who dissented were not
familiar with the relevant technology.
8 Harav Auerbach makes clear that the same ruling applies to
hearing-impaired individuals who cannot hear without a hearing aid. Igros
Moshe O.C. 4:85 is hesitant over whether a hearing aid works exactly like a
9 Women are obligated to recite Havdalah and may recite it themselves.
Although there is a well-established custom that women do not drink the wine
from the Havdalah cup, this custom is discounted when a woman needs to
fulfill her obligation of Havdalah; Mishnah Berurah 296:35; Aruch
14 If a woman refuses to recite Havdalah on her own and there is no one
available to recite it for her, her husband [or another man] may repeat it
for her, even if he has already fulfilled his obligation earlier; see
Mishnah Berurah 296:36; Aruch ha-Shulchan 296:5; Da'as Torah 296:8; Ben Ish
Chai, Vayeitzei 22. The blessing over the candle, though, should be omitted,
in the opinion of some poskim.
15 O.C. 299:5.
16 Igros Moshe O.C. 4:91-4; Tzitz Eliezer 8:11.
17 In this case, one should specifically not listen to Havdalah over the
phone, since then it may not be repeated for him when the visitor comes.
18 Mishnah Berurah 296:21. Harav S.Y. Elyashiv, too, is quoted (Yad
le-Yoledes, pg. 135) as ruling that it is better to eat before havdalah than
to listen to it over the telephone.